diff --git a/modules/openapi-generator/src/main/resources/csharp/modelEnum.mustache b/modules/openapi-generator/src/main/resources/csharp/modelEnum.mustache
index 37fb53f5f47..5562ea9fec3 100644
--- a/modules/openapi-generator/src/main/resources/csharp/modelEnum.mustache
+++ b/modules/openapi-generator/src/main/resources/csharp/modelEnum.mustache
@@ -141,7 +141,7 @@
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, {{datatypeWithEnum}}{{^datatypeWithEnum}}{{classname}}{{/datatypeWithEnum}} {{#lambda.camelcase_sanitize_param}}{{datatypeWithEnum}}{{^datatypeWithEnum}}{{classname}}{{/datatypeWithEnum}}{{/lambda.camelcase_sanitize_param}}, JsonSerializerOptions options)
         {
-            writer.WriteStringValue({{#lambda.camelcase_sanitize_param}}{{datatypeWithEnum}}{{^datatypeWithEnum}}{{classname}}{{/datatypeWithEnum}}{{/lambda.camelcase_sanitize_param}}.ToString());
+            writer.WriteStringValue({{datatypeWithEnum}}{{^datatypeWithEnum}}{{classname}}{{/datatypeWithEnum}}ValueConverter.ToJsonValue({{#lambda.camelcase_sanitize_param}}{{datatypeWithEnum}}{{^datatypeWithEnum}}{{classname}}{{/datatypeWithEnum}}{{/lambda.camelcase_sanitize_param}}).ToString());
         }
     }
 
@@ -172,14 +172,14 @@
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the {{datatypeWithEnum}}{{^datatypeWithEnum}}{{classname}}{{/datatypeWithEnum}} to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="{{#lambda.camelcase_sanitize_param}}{{datatypeWithEnum}}{{^datatypeWithEnum}}{{classname}}{{/datatypeWithEnum}}{{/lambda.camelcase_sanitize_param}}"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, {{datatypeWithEnum}}{{^datatypeWithEnum}}{{classname}}{{/datatypeWithEnum}}? {{#lambda.camelcase_sanitize_param}}{{datatypeWithEnum}}{{^datatypeWithEnum}}{{classname}}{{/datatypeWithEnum}}{{/lambda.camelcase_sanitize_param}}, JsonSerializerOptions options)
         {
-            writer.WriteStringValue({{#lambda.camelcase_sanitize_param}}{{datatypeWithEnum}}{{^datatypeWithEnum}}{{classname}}{{/datatypeWithEnum}}{{/lambda.camelcase_sanitize_param}}?.ToString() ?? "null");
+            writer.WriteStringValue({{#lambda.camelcase_sanitize_param}}{{datatypeWithEnum}}{{^datatypeWithEnum}}{{classname}}{{/datatypeWithEnum}}{{/lambda.camelcase_sanitize_param}}.HasValue ? {{datatypeWithEnum}}{{^datatypeWithEnum}}{{classname}}{{/datatypeWithEnum}}ValueConverter.ToJsonValue({{#lambda.camelcase_sanitize_param}}{{datatypeWithEnum}}{{^datatypeWithEnum}}{{classname}}{{/datatypeWithEnum}}{{/lambda.camelcase_sanitize_param}}.Value).ToString() : "null");
         }
     }
     {{/useGenericHost}}
diff --git a/samples/client/petstore/csharp/generichost/latest/ComposedEnum/src/Org.OpenAPITools/Model/MarineAreaCode.cs b/samples/client/petstore/csharp/generichost/latest/ComposedEnum/src/Org.OpenAPITools/Model/MarineAreaCode.cs
index 57a76d49d32..73e3e9e0c3d 100644
--- a/samples/client/petstore/csharp/generichost/latest/ComposedEnum/src/Org.OpenAPITools/Model/MarineAreaCode.cs
+++ b/samples/client/petstore/csharp/generichost/latest/ComposedEnum/src/Org.OpenAPITools/Model/MarineAreaCode.cs
@@ -131,7 +131,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, MarineAreaCode marineAreaCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(marineAreaCode.ToString());
+            writer.WriteStringValue(MarineAreaCodeValueConverter.ToJsonValue(marineAreaCode).ToString());
         }
     }
 
@@ -162,14 +162,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the MarineAreaCode to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="marineAreaCode"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, MarineAreaCode? marineAreaCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(marineAreaCode?.ToString() ?? "null");
+            writer.WriteStringValue(marineAreaCode.HasValue ? MarineAreaCodeValueConverter.ToJsonValue(marineAreaCode.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/latest/ComposedEnum/src/Org.OpenAPITools/Model/StateTerritoryCode.cs b/samples/client/petstore/csharp/generichost/latest/ComposedEnum/src/Org.OpenAPITools/Model/StateTerritoryCode.cs
index 3889d46b121..f2e57c7ceec 100644
--- a/samples/client/petstore/csharp/generichost/latest/ComposedEnum/src/Org.OpenAPITools/Model/StateTerritoryCode.cs
+++ b/samples/client/petstore/csharp/generichost/latest/ComposedEnum/src/Org.OpenAPITools/Model/StateTerritoryCode.cs
@@ -131,7 +131,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, StateTerritoryCode stateTerritoryCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(stateTerritoryCode.ToString());
+            writer.WriteStringValue(StateTerritoryCodeValueConverter.ToJsonValue(stateTerritoryCode).ToString());
         }
     }
 
@@ -162,14 +162,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the StateTerritoryCode to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="stateTerritoryCode"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, StateTerritoryCode? stateTerritoryCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(stateTerritoryCode?.ToString() ?? "null");
+            writer.WriteStringValue(stateTerritoryCode.HasValue ? StateTerritoryCodeValueConverter.ToJsonValue(stateTerritoryCode.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/ChildCatAllOfPetType.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/ChildCatAllOfPetType.cs
index 9e8bc253fdb..252a51260bc 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/ChildCatAllOfPetType.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/ChildCatAllOfPetType.cs
@@ -116,7 +116,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ChildCatAllOfPetType childCatAllOfPetType, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(childCatAllOfPetType.ToString());
+            writer.WriteStringValue(ChildCatAllOfPetTypeValueConverter.ToJsonValue(childCatAllOfPetType).ToString());
         }
     }
 
@@ -147,14 +147,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the ChildCatAllOfPetType to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="childCatAllOfPetType"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ChildCatAllOfPetType? childCatAllOfPetType, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(childCatAllOfPetType?.ToString() ?? "null");
+            writer.WriteStringValue(childCatAllOfPetType.HasValue ? ChildCatAllOfPetTypeValueConverter.ToJsonValue(childCatAllOfPetType.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumArraysArrayEnumInner.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumArraysArrayEnumInner.cs
index c620b7197c4..2ceb96620d0 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumArraysArrayEnumInner.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumArraysArrayEnumInner.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumArraysArrayEnumInner enumArraysArrayEnumInner, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumArraysArrayEnumInner.ToString());
+            writer.WriteStringValue(EnumArraysArrayEnumInnerValueConverter.ToJsonValue(enumArraysArrayEnumInner).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumArraysArrayEnumInner to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumArraysArrayEnumInner"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumArraysArrayEnumInner? enumArraysArrayEnumInner, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumArraysArrayEnumInner?.ToString() ?? "null");
+            writer.WriteStringValue(enumArraysArrayEnumInner.HasValue ? EnumArraysArrayEnumInnerValueConverter.ToJsonValue(enumArraysArrayEnumInner.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumArraysJustSymbol.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumArraysJustSymbol.cs
index 4a414d11d0d..8400d5cd427 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumArraysJustSymbol.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumArraysJustSymbol.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumArraysJustSymbol enumArraysJustSymbol, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumArraysJustSymbol.ToString());
+            writer.WriteStringValue(EnumArraysJustSymbolValueConverter.ToJsonValue(enumArraysJustSymbol).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumArraysJustSymbol to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumArraysJustSymbol"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumArraysJustSymbol? enumArraysJustSymbol, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumArraysJustSymbol?.ToString() ?? "null");
+            writer.WriteStringValue(enumArraysJustSymbol.HasValue ? EnumArraysJustSymbolValueConverter.ToJsonValue(enumArraysJustSymbol.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumClass.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumClass.cs
index b1aff0adf0d..cefbf28588f 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumClass.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumClass.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass.ToString());
+            writer.WriteStringValue(EnumClassValueConverter.ToJsonValue(enumClass).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumClass to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumClass"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass? enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass?.ToString() ?? "null");
+            writer.WriteStringValue(enumClass.HasValue ? EnumClassValueConverter.ToJsonValue(enumClass.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumInteger.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumInteger.cs
index 3a1302bf271..19178ecba28 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumInteger.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumInteger.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumInteger enumTestEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumInteger.ToString());
+            writer.WriteStringValue(EnumTestEnumIntegerValueConverter.ToJsonValue(enumTestEnumInteger).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumTestEnumInteger to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumTestEnumInteger"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumInteger? enumTestEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumInteger?.ToString() ?? "null");
+            writer.WriteStringValue(enumTestEnumInteger.HasValue ? EnumTestEnumIntegerValueConverter.ToJsonValue(enumTestEnumInteger.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumIntegerOnly.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumIntegerOnly.cs
index cd0add6cf3c..6a999c69d57 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumIntegerOnly.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumIntegerOnly.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumIntegerOnly enumTestEnumIntegerOnly, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumIntegerOnly.ToString());
+            writer.WriteStringValue(EnumTestEnumIntegerOnlyValueConverter.ToJsonValue(enumTestEnumIntegerOnly).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumTestEnumIntegerOnly to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumTestEnumIntegerOnly"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumIntegerOnly? enumTestEnumIntegerOnly, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumIntegerOnly?.ToString() ?? "null");
+            writer.WriteStringValue(enumTestEnumIntegerOnly.HasValue ? EnumTestEnumIntegerOnlyValueConverter.ToJsonValue(enumTestEnumIntegerOnly.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumString.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumString.cs
index adad28355b7..4d02eeaec01 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumString.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumString.cs
@@ -214,7 +214,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumString enumTestEnumString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumString.ToString());
+            writer.WriteStringValue(EnumTestEnumStringValueConverter.ToJsonValue(enumTestEnumString).ToString());
         }
     }
 
@@ -245,14 +245,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumTestEnumString to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumTestEnumString"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumString? enumTestEnumString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumString?.ToString() ?? "null");
+            writer.WriteStringValue(enumTestEnumString.HasValue ? EnumTestEnumStringValueConverter.ToJsonValue(enumTestEnumString.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/FindPetsByStatusStatusParameterInner.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/FindPetsByStatusStatusParameterInner.cs
index da357d93dd2..e7f98f931cc 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/FindPetsByStatusStatusParameterInner.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/FindPetsByStatusStatusParameterInner.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, FindPetsByStatusStatusParameterInner findPetsByStatusStatusParameterInner, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(findPetsByStatusStatusParameterInner.ToString());
+            writer.WriteStringValue(FindPetsByStatusStatusParameterInnerValueConverter.ToJsonValue(findPetsByStatusStatusParameterInner).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the FindPetsByStatusStatusParameterInner to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="findPetsByStatusStatusParameterInner"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, FindPetsByStatusStatusParameterInner? findPetsByStatusStatusParameterInner, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(findPetsByStatusStatusParameterInner?.ToString() ?? "null");
+            writer.WriteStringValue(findPetsByStatusStatusParameterInner.HasValue ? FindPetsByStatusStatusParameterInnerValueConverter.ToJsonValue(findPetsByStatusStatusParameterInner.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/MapTestMapOfEnumStringValue.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/MapTestMapOfEnumStringValue.cs
index 441ea5dcb7d..3c7331f80f2 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/MapTestMapOfEnumStringValue.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/MapTestMapOfEnumStringValue.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, MapTestMapOfEnumStringValue mapTestMapOfEnumStringValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(mapTestMapOfEnumStringValue.ToString());
+            writer.WriteStringValue(MapTestMapOfEnumStringValueValueConverter.ToJsonValue(mapTestMapOfEnumStringValue).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the MapTestMapOfEnumStringValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="mapTestMapOfEnumStringValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, MapTestMapOfEnumStringValue? mapTestMapOfEnumStringValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(mapTestMapOfEnumStringValue?.ToString() ?? "null");
+            writer.WriteStringValue(mapTestMapOfEnumStringValue.HasValue ? MapTestMapOfEnumStringValueValueConverter.ToJsonValue(mapTestMapOfEnumStringValue.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/OrderStatus.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/OrderStatus.cs
index 6566ca4aa56..cd0ff06ce52 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/OrderStatus.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/OrderStatus.cs
@@ -145,7 +145,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OrderStatus orderStatus, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(orderStatus.ToString());
+            writer.WriteStringValue(OrderStatusValueConverter.ToJsonValue(orderStatus).ToString());
         }
     }
 
@@ -176,14 +176,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OrderStatus to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="orderStatus"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OrderStatus? orderStatus, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(orderStatus?.ToString() ?? "null");
+            writer.WriteStringValue(orderStatus.HasValue ? OrderStatusValueConverter.ToJsonValue(orderStatus.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/OuterEnum.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/OuterEnum.cs
index 47bb6793c6a..e72ea52b087 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/OuterEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/OuterEnum.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnum outerEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnum.ToString());
+            writer.WriteStringValue(OuterEnumValueConverter.ToJsonValue(outerEnum).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnum? outerEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnum?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnum.HasValue ? OuterEnumValueConverter.ToJsonValue(outerEnum.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
index 136fb4c54c4..e2c52f962f3 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumDefaultValue outerEnumDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumDefaultValue.ToString());
+            writer.WriteStringValue(OuterEnumDefaultValueValueConverter.ToJsonValue(outerEnumDefaultValue).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumDefaultValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumDefaultValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumDefaultValue? outerEnumDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumDefaultValue?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumDefaultValue.HasValue ? OuterEnumDefaultValueValueConverter.ToJsonValue(outerEnumDefaultValue.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/OuterEnumInteger.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
index 2ed4f18a657..e3812cb3198 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
@@ -135,7 +135,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumInteger outerEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumInteger.ToString());
+            writer.WriteStringValue(OuterEnumIntegerValueConverter.ToJsonValue(outerEnumInteger).ToString());
         }
     }
 
@@ -166,14 +166,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumInteger to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumInteger"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumInteger? outerEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumInteger?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumInteger.HasValue ? OuterEnumIntegerValueConverter.ToJsonValue(outerEnumInteger.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
index c6a470cc64d..296151997b0 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
@@ -135,7 +135,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumIntegerDefaultValue outerEnumIntegerDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumIntegerDefaultValue.ToString());
+            writer.WriteStringValue(OuterEnumIntegerDefaultValueValueConverter.ToJsonValue(outerEnumIntegerDefaultValue).ToString());
         }
     }
 
@@ -166,14 +166,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumIntegerDefaultValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumIntegerDefaultValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumIntegerDefaultValue? outerEnumIntegerDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumIntegerDefaultValue?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumIntegerDefaultValue.HasValue ? OuterEnumIntegerDefaultValueValueConverter.ToJsonValue(outerEnumIntegerDefaultValue.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/OuterEnumTest.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/OuterEnumTest.cs
index a2e789f2ede..b4c4e25a9bb 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/OuterEnumTest.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/OuterEnumTest.cs
@@ -214,7 +214,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumTest outerEnumTest, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumTest.ToString());
+            writer.WriteStringValue(OuterEnumTestValueConverter.ToJsonValue(outerEnumTest).ToString());
         }
     }
 
@@ -245,14 +245,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumTest to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumTest"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumTest? outerEnumTest, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumTest?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumTest.HasValue ? OuterEnumTestValueConverter.ToJsonValue(outerEnumTest.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/PetStatus.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/PetStatus.cs
index 9e19b612bf9..52de1419c80 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/PetStatus.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/PetStatus.cs
@@ -145,7 +145,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, PetStatus petStatus, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(petStatus.ToString());
+            writer.WriteStringValue(PetStatusValueConverter.ToJsonValue(petStatus).ToString());
         }
     }
 
@@ -176,14 +176,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the PetStatus to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="petStatus"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, PetStatus? petStatus, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(petStatus?.ToString() ?? "null");
+            writer.WriteStringValue(petStatus.HasValue ? PetStatusValueConverter.ToJsonValue(petStatus.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumInteger.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumInteger.cs
index 04988ef3ee9..fcdc5507481 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumInteger.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumInteger.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNotnullableEnumInteger requiredClassRequiredNotnullableEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNotnullableEnumInteger.ToString());
+            writer.WriteStringValue(RequiredClassRequiredNotnullableEnumIntegerValueConverter.ToJsonValue(requiredClassRequiredNotnullableEnumInteger).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the RequiredClassRequiredNotnullableEnumInteger to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="requiredClassRequiredNotnullableEnumInteger"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNotnullableEnumInteger? requiredClassRequiredNotnullableEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNotnullableEnumInteger?.ToString() ?? "null");
+            writer.WriteStringValue(requiredClassRequiredNotnullableEnumInteger.HasValue ? RequiredClassRequiredNotnullableEnumIntegerValueConverter.ToJsonValue(requiredClassRequiredNotnullableEnumInteger.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumIntegerOnly.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumIntegerOnly.cs
index 775aba4f6af..1d33399c633 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumIntegerOnly.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumIntegerOnly.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNotnullableEnumIntegerOnly requiredClassRequiredNotnullableEnumIntegerOnly, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNotnullableEnumIntegerOnly.ToString());
+            writer.WriteStringValue(RequiredClassRequiredNotnullableEnumIntegerOnlyValueConverter.ToJsonValue(requiredClassRequiredNotnullableEnumIntegerOnly).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the RequiredClassRequiredNotnullableEnumIntegerOnly to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="requiredClassRequiredNotnullableEnumIntegerOnly"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNotnullableEnumIntegerOnly? requiredClassRequiredNotnullableEnumIntegerOnly, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNotnullableEnumIntegerOnly?.ToString() ?? "null");
+            writer.WriteStringValue(requiredClassRequiredNotnullableEnumIntegerOnly.HasValue ? RequiredClassRequiredNotnullableEnumIntegerOnlyValueConverter.ToJsonValue(requiredClassRequiredNotnullableEnumIntegerOnly.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumString.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumString.cs
index 5b4f29294ac..1e251fee921 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumString.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumString.cs
@@ -214,7 +214,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNotnullableEnumString requiredClassRequiredNotnullableEnumString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNotnullableEnumString.ToString());
+            writer.WriteStringValue(RequiredClassRequiredNotnullableEnumStringValueConverter.ToJsonValue(requiredClassRequiredNotnullableEnumString).ToString());
         }
     }
 
@@ -245,14 +245,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the RequiredClassRequiredNotnullableEnumString to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="requiredClassRequiredNotnullableEnumString"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNotnullableEnumString? requiredClassRequiredNotnullableEnumString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNotnullableEnumString?.ToString() ?? "null");
+            writer.WriteStringValue(requiredClassRequiredNotnullableEnumString.HasValue ? RequiredClassRequiredNotnullableEnumStringValueConverter.ToJsonValue(requiredClassRequiredNotnullableEnumString.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumInteger.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumInteger.cs
index 365504a241b..97db2037f95 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumInteger.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumInteger.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNullableEnumInteger requiredClassRequiredNullableEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNullableEnumInteger.ToString());
+            writer.WriteStringValue(RequiredClassRequiredNullableEnumIntegerValueConverter.ToJsonValue(requiredClassRequiredNullableEnumInteger).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the RequiredClassRequiredNullableEnumInteger to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="requiredClassRequiredNullableEnumInteger"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNullableEnumInteger? requiredClassRequiredNullableEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNullableEnumInteger?.ToString() ?? "null");
+            writer.WriteStringValue(requiredClassRequiredNullableEnumInteger.HasValue ? RequiredClassRequiredNullableEnumIntegerValueConverter.ToJsonValue(requiredClassRequiredNullableEnumInteger.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumIntegerOnly.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumIntegerOnly.cs
index 4c5f2c56ba5..2f53261cd6f 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumIntegerOnly.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumIntegerOnly.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNullableEnumIntegerOnly requiredClassRequiredNullableEnumIntegerOnly, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNullableEnumIntegerOnly.ToString());
+            writer.WriteStringValue(RequiredClassRequiredNullableEnumIntegerOnlyValueConverter.ToJsonValue(requiredClassRequiredNullableEnumIntegerOnly).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the RequiredClassRequiredNullableEnumIntegerOnly to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="requiredClassRequiredNullableEnumIntegerOnly"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNullableEnumIntegerOnly? requiredClassRequiredNullableEnumIntegerOnly, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNullableEnumIntegerOnly?.ToString() ?? "null");
+            writer.WriteStringValue(requiredClassRequiredNullableEnumIntegerOnly.HasValue ? RequiredClassRequiredNullableEnumIntegerOnlyValueConverter.ToJsonValue(requiredClassRequiredNullableEnumIntegerOnly.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumString.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumString.cs
index 36bcb148131..7efe892e924 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumString.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumString.cs
@@ -214,7 +214,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNullableEnumString requiredClassRequiredNullableEnumString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNullableEnumString.ToString());
+            writer.WriteStringValue(RequiredClassRequiredNullableEnumStringValueConverter.ToJsonValue(requiredClassRequiredNullableEnumString).ToString());
         }
     }
 
@@ -245,14 +245,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the RequiredClassRequiredNullableEnumString to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="requiredClassRequiredNullableEnumString"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNullableEnumString? requiredClassRequiredNullableEnumString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNullableEnumString?.ToString() ?? "null");
+            writer.WriteStringValue(requiredClassRequiredNullableEnumString.HasValue ? RequiredClassRequiredNullableEnumStringValueConverter.ToJsonValue(requiredClassRequiredNullableEnumString.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestDescendantsObjectType.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestDescendantsObjectType.cs
index 32fdf9b1c3b..0c0c757cc59 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestDescendantsObjectType.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestDescendantsObjectType.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestDescendantsObjectType testDescendantsObjectType, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testDescendantsObjectType.ToString());
+            writer.WriteStringValue(TestDescendantsObjectTypeValueConverter.ToJsonValue(testDescendantsObjectType).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestDescendantsObjectType to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testDescendantsObjectType"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestDescendantsObjectType? testDescendantsObjectType, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testDescendantsObjectType?.ToString() ?? "null");
+            writer.WriteStringValue(testDescendantsObjectType.HasValue ? TestDescendantsObjectTypeValueConverter.ToJsonValue(testDescendantsObjectType.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumHeaderStringParameter.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumHeaderStringParameter.cs
index ccb446b0250..4fe8d2deb70 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumHeaderStringParameter.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumHeaderStringParameter.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersEnumHeaderStringParameter testEnumParametersEnumHeaderStringParameter, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersEnumHeaderStringParameter.ToString());
+            writer.WriteStringValue(TestEnumParametersEnumHeaderStringParameterValueConverter.ToJsonValue(testEnumParametersEnumHeaderStringParameter).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestEnumParametersEnumHeaderStringParameter to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testEnumParametersEnumHeaderStringParameter"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersEnumHeaderStringParameter? testEnumParametersEnumHeaderStringParameter, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersEnumHeaderStringParameter?.ToString() ?? "null");
+            writer.WriteStringValue(testEnumParametersEnumHeaderStringParameter.HasValue ? TestEnumParametersEnumHeaderStringParameterValueConverter.ToJsonValue(testEnumParametersEnumHeaderStringParameter.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryDoubleParameter.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryDoubleParameter.cs
index ec14b39944d..d4d97e76043 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryDoubleParameter.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryDoubleParameter.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersEnumQueryDoubleParameter testEnumParametersEnumQueryDoubleParameter, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersEnumQueryDoubleParameter.ToString());
+            writer.WriteStringValue(TestEnumParametersEnumQueryDoubleParameterValueConverter.ToJsonValue(testEnumParametersEnumQueryDoubleParameter).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestEnumParametersEnumQueryDoubleParameter to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testEnumParametersEnumQueryDoubleParameter"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersEnumQueryDoubleParameter? testEnumParametersEnumQueryDoubleParameter, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersEnumQueryDoubleParameter?.ToString() ?? "null");
+            writer.WriteStringValue(testEnumParametersEnumQueryDoubleParameter.HasValue ? TestEnumParametersEnumQueryDoubleParameterValueConverter.ToJsonValue(testEnumParametersEnumQueryDoubleParameter.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryIntegerParameter.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryIntegerParameter.cs
index 33ff2ce2cc2..85149c3f5eb 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryIntegerParameter.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryIntegerParameter.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersEnumQueryIntegerParameter testEnumParametersEnumQueryIntegerParameter, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersEnumQueryIntegerParameter.ToString());
+            writer.WriteStringValue(TestEnumParametersEnumQueryIntegerParameterValueConverter.ToJsonValue(testEnumParametersEnumQueryIntegerParameter).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestEnumParametersEnumQueryIntegerParameter to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testEnumParametersEnumQueryIntegerParameter"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersEnumQueryIntegerParameter? testEnumParametersEnumQueryIntegerParameter, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersEnumQueryIntegerParameter?.ToString() ?? "null");
+            writer.WriteStringValue(testEnumParametersEnumQueryIntegerParameter.HasValue ? TestEnumParametersEnumQueryIntegerParameterValueConverter.ToJsonValue(testEnumParametersEnumQueryIntegerParameter.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormString.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormString.cs
index d86b48d4a9b..2e81a11c33b 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormString.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormString.cs
@@ -145,7 +145,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersRequestEnumFormString testEnumParametersRequestEnumFormString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersRequestEnumFormString.ToString());
+            writer.WriteStringValue(TestEnumParametersRequestEnumFormStringValueConverter.ToJsonValue(testEnumParametersRequestEnumFormString).ToString());
         }
     }
 
@@ -176,14 +176,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestEnumParametersRequestEnumFormString to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testEnumParametersRequestEnumFormString"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersRequestEnumFormString? testEnumParametersRequestEnumFormString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersRequestEnumFormString?.ToString() ?? "null");
+            writer.WriteStringValue(testEnumParametersRequestEnumFormString.HasValue ? TestEnumParametersRequestEnumFormStringValueConverter.ToJsonValue(testEnumParametersRequestEnumFormString.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormStringArrayInner.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormStringArrayInner.cs
index 4f1c9c53c60..5c00030c30a 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormStringArrayInner.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormStringArrayInner.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersRequestEnumFormStringArrayInner testEnumParametersRequestEnumFormStringArrayInner, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersRequestEnumFormStringArrayInner.ToString());
+            writer.WriteStringValue(TestEnumParametersRequestEnumFormStringArrayInnerValueConverter.ToJsonValue(testEnumParametersRequestEnumFormStringArrayInner).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestEnumParametersRequestEnumFormStringArrayInner to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testEnumParametersRequestEnumFormStringArrayInner"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersRequestEnumFormStringArrayInner? testEnumParametersRequestEnumFormStringArrayInner, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersRequestEnumFormStringArrayInner?.ToString() ?? "null");
+            writer.WriteStringValue(testEnumParametersRequestEnumFormStringArrayInner.HasValue ? TestEnumParametersRequestEnumFormStringArrayInnerValueConverter.ToJsonValue(testEnumParametersRequestEnumFormStringArrayInner.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestResultCode.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestResultCode.cs
index 0fc06c04a67..280c9b82cfa 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestResultCode.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/TestResultCode.cs
@@ -131,7 +131,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestResultCode testResultCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testResultCode.ToString());
+            writer.WriteStringValue(TestResultCodeValueConverter.ToJsonValue(testResultCode).ToString());
         }
     }
 
@@ -162,14 +162,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestResultCode to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testResultCode"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestResultCode? testResultCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testResultCode?.ToString() ?? "null");
+            writer.WriteStringValue(testResultCode.HasValue ? TestResultCodeValueConverter.ToJsonValue(testResultCode.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/ZebraType.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/ZebraType.cs
index 4a54f2a265a..5eb8d6bac71 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/ZebraType.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/ZebraType.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZebraType zebraType, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zebraType.ToString());
+            writer.WriteStringValue(ZebraTypeValueConverter.ToJsonValue(zebraType).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the ZebraType to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="zebraType"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZebraType? zebraType, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zebraType?.ToString() ?? "null");
+            writer.WriteStringValue(zebraType.HasValue ? ZebraTypeValueConverter.ToJsonValue(zebraType.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
index 34a044fb8b1..b82155f7800 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnum zeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnum.ToString());
+            writer.WriteStringValue(ZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnum).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the ZeroBasedEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="zeroBasedEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnum? zeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnum?.ToString() ?? "null");
+            writer.WriteStringValue(zeroBasedEnum.HasValue ? ZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnum.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnumClassZeroBasedEnum.cs b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnumClassZeroBasedEnum.cs
index 2b062a550ab..cb6f10e40b3 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnumClassZeroBasedEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnumClassZeroBasedEnum.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnumClassZeroBasedEnum zeroBasedEnumClassZeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnumClassZeroBasedEnum.ToString());
+            writer.WriteStringValue(ZeroBasedEnumClassZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnumClassZeroBasedEnum).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the ZeroBasedEnumClassZeroBasedEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="zeroBasedEnumClassZeroBasedEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnumClassZeroBasedEnum? zeroBasedEnumClassZeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnumClassZeroBasedEnum?.ToString() ?? "null");
+            writer.WriteStringValue(zeroBasedEnumClassZeroBasedEnum.HasValue ? ZeroBasedEnumClassZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnumClassZeroBasedEnum.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/EnumClass.cs b/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/EnumClass.cs
index b1aff0adf0d..cefbf28588f 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/EnumClass.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/EnumClass.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass.ToString());
+            writer.WriteStringValue(EnumClassValueConverter.ToJsonValue(enumClass).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumClass to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumClass"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass? enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass?.ToString() ?? "null");
+            writer.WriteStringValue(enumClass.HasValue ? EnumClassValueConverter.ToJsonValue(enumClass.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/OuterEnum.cs b/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/OuterEnum.cs
index 47bb6793c6a..e72ea52b087 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/OuterEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/OuterEnum.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnum outerEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnum.ToString());
+            writer.WriteStringValue(OuterEnumValueConverter.ToJsonValue(outerEnum).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnum? outerEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnum?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnum.HasValue ? OuterEnumValueConverter.ToJsonValue(outerEnum.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs b/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
index 136fb4c54c4..e2c52f962f3 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumDefaultValue outerEnumDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumDefaultValue.ToString());
+            writer.WriteStringValue(OuterEnumDefaultValueValueConverter.ToJsonValue(outerEnumDefaultValue).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumDefaultValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumDefaultValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumDefaultValue? outerEnumDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumDefaultValue?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumDefaultValue.HasValue ? OuterEnumDefaultValueValueConverter.ToJsonValue(outerEnumDefaultValue.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/OuterEnumInteger.cs b/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
index 2ed4f18a657..e3812cb3198 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
@@ -135,7 +135,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumInteger outerEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumInteger.ToString());
+            writer.WriteStringValue(OuterEnumIntegerValueConverter.ToJsonValue(outerEnumInteger).ToString());
         }
     }
 
@@ -166,14 +166,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumInteger to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumInteger"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumInteger? outerEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumInteger?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumInteger.HasValue ? OuterEnumIntegerValueConverter.ToJsonValue(outerEnumInteger.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs b/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
index c6a470cc64d..296151997b0 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
@@ -135,7 +135,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumIntegerDefaultValue outerEnumIntegerDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumIntegerDefaultValue.ToString());
+            writer.WriteStringValue(OuterEnumIntegerDefaultValueValueConverter.ToJsonValue(outerEnumIntegerDefaultValue).ToString());
         }
     }
 
@@ -166,14 +166,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumIntegerDefaultValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumIntegerDefaultValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumIntegerDefaultValue? outerEnumIntegerDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumIntegerDefaultValue?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumIntegerDefaultValue.HasValue ? OuterEnumIntegerDefaultValueValueConverter.ToJsonValue(outerEnumIntegerDefaultValue.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/OuterEnumTest.cs b/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/OuterEnumTest.cs
index a2e789f2ede..b4c4e25a9bb 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/OuterEnumTest.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/OuterEnumTest.cs
@@ -214,7 +214,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumTest outerEnumTest, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumTest.ToString());
+            writer.WriteStringValue(OuterEnumTestValueConverter.ToJsonValue(outerEnumTest).ToString());
         }
     }
 
@@ -245,14 +245,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumTest to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumTest"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumTest? outerEnumTest, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumTest?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumTest.HasValue ? OuterEnumTestValueConverter.ToJsonValue(outerEnumTest.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/TestResultCode.cs b/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/TestResultCode.cs
index 0fc06c04a67..280c9b82cfa 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/TestResultCode.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/TestResultCode.cs
@@ -131,7 +131,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestResultCode testResultCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testResultCode.ToString());
+            writer.WriteStringValue(TestResultCodeValueConverter.ToJsonValue(testResultCode).ToString());
         }
     }
 
@@ -162,14 +162,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestResultCode to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testResultCode"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestResultCode? testResultCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testResultCode?.ToString() ?? "null");
+            writer.WriteStringValue(testResultCode.HasValue ? TestResultCodeValueConverter.ToJsonValue(testResultCode.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs b/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
index 34a044fb8b1..b82155f7800 100644
--- a/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net4.7/Petstore/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnum zeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnum.ToString());
+            writer.WriteStringValue(ZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnum).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the ZeroBasedEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="zeroBasedEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnum? zeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnum?.ToString() ?? "null");
+            writer.WriteStringValue(zeroBasedEnum.HasValue ? ZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnum.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/ChildCatAllOfPetType.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/ChildCatAllOfPetType.cs
index 9e8bc253fdb..252a51260bc 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/ChildCatAllOfPetType.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/ChildCatAllOfPetType.cs
@@ -116,7 +116,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ChildCatAllOfPetType childCatAllOfPetType, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(childCatAllOfPetType.ToString());
+            writer.WriteStringValue(ChildCatAllOfPetTypeValueConverter.ToJsonValue(childCatAllOfPetType).ToString());
         }
     }
 
@@ -147,14 +147,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the ChildCatAllOfPetType to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="childCatAllOfPetType"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ChildCatAllOfPetType? childCatAllOfPetType, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(childCatAllOfPetType?.ToString() ?? "null");
+            writer.WriteStringValue(childCatAllOfPetType.HasValue ? ChildCatAllOfPetTypeValueConverter.ToJsonValue(childCatAllOfPetType.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/EnumArraysArrayEnumInner.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/EnumArraysArrayEnumInner.cs
index c620b7197c4..2ceb96620d0 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/EnumArraysArrayEnumInner.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/EnumArraysArrayEnumInner.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumArraysArrayEnumInner enumArraysArrayEnumInner, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumArraysArrayEnumInner.ToString());
+            writer.WriteStringValue(EnumArraysArrayEnumInnerValueConverter.ToJsonValue(enumArraysArrayEnumInner).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumArraysArrayEnumInner to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumArraysArrayEnumInner"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumArraysArrayEnumInner? enumArraysArrayEnumInner, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumArraysArrayEnumInner?.ToString() ?? "null");
+            writer.WriteStringValue(enumArraysArrayEnumInner.HasValue ? EnumArraysArrayEnumInnerValueConverter.ToJsonValue(enumArraysArrayEnumInner.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/EnumArraysJustSymbol.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/EnumArraysJustSymbol.cs
index 4a414d11d0d..8400d5cd427 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/EnumArraysJustSymbol.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/EnumArraysJustSymbol.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumArraysJustSymbol enumArraysJustSymbol, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumArraysJustSymbol.ToString());
+            writer.WriteStringValue(EnumArraysJustSymbolValueConverter.ToJsonValue(enumArraysJustSymbol).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumArraysJustSymbol to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumArraysJustSymbol"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumArraysJustSymbol? enumArraysJustSymbol, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumArraysJustSymbol?.ToString() ?? "null");
+            writer.WriteStringValue(enumArraysJustSymbol.HasValue ? EnumArraysJustSymbolValueConverter.ToJsonValue(enumArraysJustSymbol.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/EnumClass.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/EnumClass.cs
index b1aff0adf0d..cefbf28588f 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/EnumClass.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/EnumClass.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass.ToString());
+            writer.WriteStringValue(EnumClassValueConverter.ToJsonValue(enumClass).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumClass to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumClass"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass? enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass?.ToString() ?? "null");
+            writer.WriteStringValue(enumClass.HasValue ? EnumClassValueConverter.ToJsonValue(enumClass.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumInteger.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumInteger.cs
index 3a1302bf271..19178ecba28 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumInteger.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumInteger.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumInteger enumTestEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumInteger.ToString());
+            writer.WriteStringValue(EnumTestEnumIntegerValueConverter.ToJsonValue(enumTestEnumInteger).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumTestEnumInteger to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumTestEnumInteger"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumInteger? enumTestEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumInteger?.ToString() ?? "null");
+            writer.WriteStringValue(enumTestEnumInteger.HasValue ? EnumTestEnumIntegerValueConverter.ToJsonValue(enumTestEnumInteger.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumIntegerOnly.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumIntegerOnly.cs
index cd0add6cf3c..6a999c69d57 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumIntegerOnly.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumIntegerOnly.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumIntegerOnly enumTestEnumIntegerOnly, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumIntegerOnly.ToString());
+            writer.WriteStringValue(EnumTestEnumIntegerOnlyValueConverter.ToJsonValue(enumTestEnumIntegerOnly).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumTestEnumIntegerOnly to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumTestEnumIntegerOnly"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumIntegerOnly? enumTestEnumIntegerOnly, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumIntegerOnly?.ToString() ?? "null");
+            writer.WriteStringValue(enumTestEnumIntegerOnly.HasValue ? EnumTestEnumIntegerOnlyValueConverter.ToJsonValue(enumTestEnumIntegerOnly.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumString.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumString.cs
index adad28355b7..4d02eeaec01 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumString.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumString.cs
@@ -214,7 +214,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumString enumTestEnumString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumString.ToString());
+            writer.WriteStringValue(EnumTestEnumStringValueConverter.ToJsonValue(enumTestEnumString).ToString());
         }
     }
 
@@ -245,14 +245,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumTestEnumString to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumTestEnumString"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumString? enumTestEnumString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumString?.ToString() ?? "null");
+            writer.WriteStringValue(enumTestEnumString.HasValue ? EnumTestEnumStringValueConverter.ToJsonValue(enumTestEnumString.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/FindPetsByStatusStatusParameterInner.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/FindPetsByStatusStatusParameterInner.cs
index da357d93dd2..e7f98f931cc 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/FindPetsByStatusStatusParameterInner.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/FindPetsByStatusStatusParameterInner.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, FindPetsByStatusStatusParameterInner findPetsByStatusStatusParameterInner, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(findPetsByStatusStatusParameterInner.ToString());
+            writer.WriteStringValue(FindPetsByStatusStatusParameterInnerValueConverter.ToJsonValue(findPetsByStatusStatusParameterInner).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the FindPetsByStatusStatusParameterInner to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="findPetsByStatusStatusParameterInner"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, FindPetsByStatusStatusParameterInner? findPetsByStatusStatusParameterInner, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(findPetsByStatusStatusParameterInner?.ToString() ?? "null");
+            writer.WriteStringValue(findPetsByStatusStatusParameterInner.HasValue ? FindPetsByStatusStatusParameterInnerValueConverter.ToJsonValue(findPetsByStatusStatusParameterInner.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/MapTestMapOfEnumStringValue.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/MapTestMapOfEnumStringValue.cs
index 441ea5dcb7d..3c7331f80f2 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/MapTestMapOfEnumStringValue.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/MapTestMapOfEnumStringValue.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, MapTestMapOfEnumStringValue mapTestMapOfEnumStringValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(mapTestMapOfEnumStringValue.ToString());
+            writer.WriteStringValue(MapTestMapOfEnumStringValueValueConverter.ToJsonValue(mapTestMapOfEnumStringValue).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the MapTestMapOfEnumStringValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="mapTestMapOfEnumStringValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, MapTestMapOfEnumStringValue? mapTestMapOfEnumStringValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(mapTestMapOfEnumStringValue?.ToString() ?? "null");
+            writer.WriteStringValue(mapTestMapOfEnumStringValue.HasValue ? MapTestMapOfEnumStringValueValueConverter.ToJsonValue(mapTestMapOfEnumStringValue.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/OrderStatus.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/OrderStatus.cs
index 6566ca4aa56..cd0ff06ce52 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/OrderStatus.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/OrderStatus.cs
@@ -145,7 +145,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OrderStatus orderStatus, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(orderStatus.ToString());
+            writer.WriteStringValue(OrderStatusValueConverter.ToJsonValue(orderStatus).ToString());
         }
     }
 
@@ -176,14 +176,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OrderStatus to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="orderStatus"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OrderStatus? orderStatus, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(orderStatus?.ToString() ?? "null");
+            writer.WriteStringValue(orderStatus.HasValue ? OrderStatusValueConverter.ToJsonValue(orderStatus.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/OuterEnum.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/OuterEnum.cs
index 47bb6793c6a..e72ea52b087 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/OuterEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/OuterEnum.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnum outerEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnum.ToString());
+            writer.WriteStringValue(OuterEnumValueConverter.ToJsonValue(outerEnum).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnum? outerEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnum?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnum.HasValue ? OuterEnumValueConverter.ToJsonValue(outerEnum.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
index 136fb4c54c4..e2c52f962f3 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumDefaultValue outerEnumDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumDefaultValue.ToString());
+            writer.WriteStringValue(OuterEnumDefaultValueValueConverter.ToJsonValue(outerEnumDefaultValue).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumDefaultValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumDefaultValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumDefaultValue? outerEnumDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumDefaultValue?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumDefaultValue.HasValue ? OuterEnumDefaultValueValueConverter.ToJsonValue(outerEnumDefaultValue.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/OuterEnumInteger.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
index 2ed4f18a657..e3812cb3198 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
@@ -135,7 +135,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumInteger outerEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumInteger.ToString());
+            writer.WriteStringValue(OuterEnumIntegerValueConverter.ToJsonValue(outerEnumInteger).ToString());
         }
     }
 
@@ -166,14 +166,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumInteger to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumInteger"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumInteger? outerEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumInteger?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumInteger.HasValue ? OuterEnumIntegerValueConverter.ToJsonValue(outerEnumInteger.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
index c6a470cc64d..296151997b0 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
@@ -135,7 +135,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumIntegerDefaultValue outerEnumIntegerDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumIntegerDefaultValue.ToString());
+            writer.WriteStringValue(OuterEnumIntegerDefaultValueValueConverter.ToJsonValue(outerEnumIntegerDefaultValue).ToString());
         }
     }
 
@@ -166,14 +166,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumIntegerDefaultValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumIntegerDefaultValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumIntegerDefaultValue? outerEnumIntegerDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumIntegerDefaultValue?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumIntegerDefaultValue.HasValue ? OuterEnumIntegerDefaultValueValueConverter.ToJsonValue(outerEnumIntegerDefaultValue.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/OuterEnumTest.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/OuterEnumTest.cs
index a2e789f2ede..b4c4e25a9bb 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/OuterEnumTest.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/OuterEnumTest.cs
@@ -214,7 +214,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumTest outerEnumTest, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumTest.ToString());
+            writer.WriteStringValue(OuterEnumTestValueConverter.ToJsonValue(outerEnumTest).ToString());
         }
     }
 
@@ -245,14 +245,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumTest to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumTest"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumTest? outerEnumTest, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumTest?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumTest.HasValue ? OuterEnumTestValueConverter.ToJsonValue(outerEnumTest.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/PetStatus.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/PetStatus.cs
index 9e19b612bf9..52de1419c80 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/PetStatus.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/PetStatus.cs
@@ -145,7 +145,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, PetStatus petStatus, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(petStatus.ToString());
+            writer.WriteStringValue(PetStatusValueConverter.ToJsonValue(petStatus).ToString());
         }
     }
 
@@ -176,14 +176,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the PetStatus to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="petStatus"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, PetStatus? petStatus, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(petStatus?.ToString() ?? "null");
+            writer.WriteStringValue(petStatus.HasValue ? PetStatusValueConverter.ToJsonValue(petStatus.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumInteger.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumInteger.cs
index 04988ef3ee9..fcdc5507481 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumInteger.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumInteger.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNotnullableEnumInteger requiredClassRequiredNotnullableEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNotnullableEnumInteger.ToString());
+            writer.WriteStringValue(RequiredClassRequiredNotnullableEnumIntegerValueConverter.ToJsonValue(requiredClassRequiredNotnullableEnumInteger).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the RequiredClassRequiredNotnullableEnumInteger to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="requiredClassRequiredNotnullableEnumInteger"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNotnullableEnumInteger? requiredClassRequiredNotnullableEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNotnullableEnumInteger?.ToString() ?? "null");
+            writer.WriteStringValue(requiredClassRequiredNotnullableEnumInteger.HasValue ? RequiredClassRequiredNotnullableEnumIntegerValueConverter.ToJsonValue(requiredClassRequiredNotnullableEnumInteger.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumIntegerOnly.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumIntegerOnly.cs
index 775aba4f6af..1d33399c633 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumIntegerOnly.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumIntegerOnly.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNotnullableEnumIntegerOnly requiredClassRequiredNotnullableEnumIntegerOnly, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNotnullableEnumIntegerOnly.ToString());
+            writer.WriteStringValue(RequiredClassRequiredNotnullableEnumIntegerOnlyValueConverter.ToJsonValue(requiredClassRequiredNotnullableEnumIntegerOnly).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the RequiredClassRequiredNotnullableEnumIntegerOnly to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="requiredClassRequiredNotnullableEnumIntegerOnly"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNotnullableEnumIntegerOnly? requiredClassRequiredNotnullableEnumIntegerOnly, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNotnullableEnumIntegerOnly?.ToString() ?? "null");
+            writer.WriteStringValue(requiredClassRequiredNotnullableEnumIntegerOnly.HasValue ? RequiredClassRequiredNotnullableEnumIntegerOnlyValueConverter.ToJsonValue(requiredClassRequiredNotnullableEnumIntegerOnly.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumString.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumString.cs
index 5b4f29294ac..1e251fee921 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumString.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumString.cs
@@ -214,7 +214,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNotnullableEnumString requiredClassRequiredNotnullableEnumString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNotnullableEnumString.ToString());
+            writer.WriteStringValue(RequiredClassRequiredNotnullableEnumStringValueConverter.ToJsonValue(requiredClassRequiredNotnullableEnumString).ToString());
         }
     }
 
@@ -245,14 +245,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the RequiredClassRequiredNotnullableEnumString to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="requiredClassRequiredNotnullableEnumString"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNotnullableEnumString? requiredClassRequiredNotnullableEnumString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNotnullableEnumString?.ToString() ?? "null");
+            writer.WriteStringValue(requiredClassRequiredNotnullableEnumString.HasValue ? RequiredClassRequiredNotnullableEnumStringValueConverter.ToJsonValue(requiredClassRequiredNotnullableEnumString.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumInteger.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumInteger.cs
index 365504a241b..97db2037f95 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumInteger.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumInteger.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNullableEnumInteger requiredClassRequiredNullableEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNullableEnumInteger.ToString());
+            writer.WriteStringValue(RequiredClassRequiredNullableEnumIntegerValueConverter.ToJsonValue(requiredClassRequiredNullableEnumInteger).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the RequiredClassRequiredNullableEnumInteger to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="requiredClassRequiredNullableEnumInteger"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNullableEnumInteger? requiredClassRequiredNullableEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNullableEnumInteger?.ToString() ?? "null");
+            writer.WriteStringValue(requiredClassRequiredNullableEnumInteger.HasValue ? RequiredClassRequiredNullableEnumIntegerValueConverter.ToJsonValue(requiredClassRequiredNullableEnumInteger.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumIntegerOnly.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumIntegerOnly.cs
index 4c5f2c56ba5..2f53261cd6f 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumIntegerOnly.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumIntegerOnly.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNullableEnumIntegerOnly requiredClassRequiredNullableEnumIntegerOnly, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNullableEnumIntegerOnly.ToString());
+            writer.WriteStringValue(RequiredClassRequiredNullableEnumIntegerOnlyValueConverter.ToJsonValue(requiredClassRequiredNullableEnumIntegerOnly).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the RequiredClassRequiredNullableEnumIntegerOnly to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="requiredClassRequiredNullableEnumIntegerOnly"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNullableEnumIntegerOnly? requiredClassRequiredNullableEnumIntegerOnly, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNullableEnumIntegerOnly?.ToString() ?? "null");
+            writer.WriteStringValue(requiredClassRequiredNullableEnumIntegerOnly.HasValue ? RequiredClassRequiredNullableEnumIntegerOnlyValueConverter.ToJsonValue(requiredClassRequiredNullableEnumIntegerOnly.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumString.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumString.cs
index 36bcb148131..7efe892e924 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumString.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumString.cs
@@ -214,7 +214,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNullableEnumString requiredClassRequiredNullableEnumString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNullableEnumString.ToString());
+            writer.WriteStringValue(RequiredClassRequiredNullableEnumStringValueConverter.ToJsonValue(requiredClassRequiredNullableEnumString).ToString());
         }
     }
 
@@ -245,14 +245,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the RequiredClassRequiredNullableEnumString to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="requiredClassRequiredNullableEnumString"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNullableEnumString? requiredClassRequiredNullableEnumString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNullableEnumString?.ToString() ?? "null");
+            writer.WriteStringValue(requiredClassRequiredNullableEnumString.HasValue ? RequiredClassRequiredNullableEnumStringValueConverter.ToJsonValue(requiredClassRequiredNullableEnumString.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestDescendantsObjectType.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestDescendantsObjectType.cs
index 32fdf9b1c3b..0c0c757cc59 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestDescendantsObjectType.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestDescendantsObjectType.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestDescendantsObjectType testDescendantsObjectType, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testDescendantsObjectType.ToString());
+            writer.WriteStringValue(TestDescendantsObjectTypeValueConverter.ToJsonValue(testDescendantsObjectType).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestDescendantsObjectType to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testDescendantsObjectType"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestDescendantsObjectType? testDescendantsObjectType, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testDescendantsObjectType?.ToString() ?? "null");
+            writer.WriteStringValue(testDescendantsObjectType.HasValue ? TestDescendantsObjectTypeValueConverter.ToJsonValue(testDescendantsObjectType.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumHeaderStringParameter.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumHeaderStringParameter.cs
index ccb446b0250..4fe8d2deb70 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumHeaderStringParameter.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumHeaderStringParameter.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersEnumHeaderStringParameter testEnumParametersEnumHeaderStringParameter, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersEnumHeaderStringParameter.ToString());
+            writer.WriteStringValue(TestEnumParametersEnumHeaderStringParameterValueConverter.ToJsonValue(testEnumParametersEnumHeaderStringParameter).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestEnumParametersEnumHeaderStringParameter to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testEnumParametersEnumHeaderStringParameter"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersEnumHeaderStringParameter? testEnumParametersEnumHeaderStringParameter, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersEnumHeaderStringParameter?.ToString() ?? "null");
+            writer.WriteStringValue(testEnumParametersEnumHeaderStringParameter.HasValue ? TestEnumParametersEnumHeaderStringParameterValueConverter.ToJsonValue(testEnumParametersEnumHeaderStringParameter.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryDoubleParameter.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryDoubleParameter.cs
index ec14b39944d..d4d97e76043 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryDoubleParameter.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryDoubleParameter.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersEnumQueryDoubleParameter testEnumParametersEnumQueryDoubleParameter, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersEnumQueryDoubleParameter.ToString());
+            writer.WriteStringValue(TestEnumParametersEnumQueryDoubleParameterValueConverter.ToJsonValue(testEnumParametersEnumQueryDoubleParameter).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestEnumParametersEnumQueryDoubleParameter to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testEnumParametersEnumQueryDoubleParameter"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersEnumQueryDoubleParameter? testEnumParametersEnumQueryDoubleParameter, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersEnumQueryDoubleParameter?.ToString() ?? "null");
+            writer.WriteStringValue(testEnumParametersEnumQueryDoubleParameter.HasValue ? TestEnumParametersEnumQueryDoubleParameterValueConverter.ToJsonValue(testEnumParametersEnumQueryDoubleParameter.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryIntegerParameter.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryIntegerParameter.cs
index 33ff2ce2cc2..85149c3f5eb 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryIntegerParameter.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryIntegerParameter.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersEnumQueryIntegerParameter testEnumParametersEnumQueryIntegerParameter, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersEnumQueryIntegerParameter.ToString());
+            writer.WriteStringValue(TestEnumParametersEnumQueryIntegerParameterValueConverter.ToJsonValue(testEnumParametersEnumQueryIntegerParameter).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestEnumParametersEnumQueryIntegerParameter to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testEnumParametersEnumQueryIntegerParameter"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersEnumQueryIntegerParameter? testEnumParametersEnumQueryIntegerParameter, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersEnumQueryIntegerParameter?.ToString() ?? "null");
+            writer.WriteStringValue(testEnumParametersEnumQueryIntegerParameter.HasValue ? TestEnumParametersEnumQueryIntegerParameterValueConverter.ToJsonValue(testEnumParametersEnumQueryIntegerParameter.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormString.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormString.cs
index d86b48d4a9b..2e81a11c33b 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormString.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormString.cs
@@ -145,7 +145,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersRequestEnumFormString testEnumParametersRequestEnumFormString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersRequestEnumFormString.ToString());
+            writer.WriteStringValue(TestEnumParametersRequestEnumFormStringValueConverter.ToJsonValue(testEnumParametersRequestEnumFormString).ToString());
         }
     }
 
@@ -176,14 +176,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestEnumParametersRequestEnumFormString to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testEnumParametersRequestEnumFormString"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersRequestEnumFormString? testEnumParametersRequestEnumFormString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersRequestEnumFormString?.ToString() ?? "null");
+            writer.WriteStringValue(testEnumParametersRequestEnumFormString.HasValue ? TestEnumParametersRequestEnumFormStringValueConverter.ToJsonValue(testEnumParametersRequestEnumFormString.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormStringArrayInner.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormStringArrayInner.cs
index 4f1c9c53c60..5c00030c30a 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormStringArrayInner.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormStringArrayInner.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersRequestEnumFormStringArrayInner testEnumParametersRequestEnumFormStringArrayInner, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersRequestEnumFormStringArrayInner.ToString());
+            writer.WriteStringValue(TestEnumParametersRequestEnumFormStringArrayInnerValueConverter.ToJsonValue(testEnumParametersRequestEnumFormStringArrayInner).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestEnumParametersRequestEnumFormStringArrayInner to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testEnumParametersRequestEnumFormStringArrayInner"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersRequestEnumFormStringArrayInner? testEnumParametersRequestEnumFormStringArrayInner, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersRequestEnumFormStringArrayInner?.ToString() ?? "null");
+            writer.WriteStringValue(testEnumParametersRequestEnumFormStringArrayInner.HasValue ? TestEnumParametersRequestEnumFormStringArrayInnerValueConverter.ToJsonValue(testEnumParametersRequestEnumFormStringArrayInner.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestResultCode.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestResultCode.cs
index 0fc06c04a67..280c9b82cfa 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestResultCode.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/TestResultCode.cs
@@ -131,7 +131,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestResultCode testResultCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testResultCode.ToString());
+            writer.WriteStringValue(TestResultCodeValueConverter.ToJsonValue(testResultCode).ToString());
         }
     }
 
@@ -162,14 +162,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestResultCode to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testResultCode"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestResultCode? testResultCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testResultCode?.ToString() ?? "null");
+            writer.WriteStringValue(testResultCode.HasValue ? TestResultCodeValueConverter.ToJsonValue(testResultCode.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/ZebraType.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/ZebraType.cs
index 4a54f2a265a..5eb8d6bac71 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/ZebraType.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/ZebraType.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZebraType zebraType, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zebraType.ToString());
+            writer.WriteStringValue(ZebraTypeValueConverter.ToJsonValue(zebraType).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the ZebraType to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="zebraType"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZebraType? zebraType, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zebraType?.ToString() ?? "null");
+            writer.WriteStringValue(zebraType.HasValue ? ZebraTypeValueConverter.ToJsonValue(zebraType.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
index 34a044fb8b1..b82155f7800 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnum zeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnum.ToString());
+            writer.WriteStringValue(ZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnum).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the ZeroBasedEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="zeroBasedEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnum? zeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnum?.ToString() ?? "null");
+            writer.WriteStringValue(zeroBasedEnum.HasValue ? ZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnum.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnumClassZeroBasedEnum.cs b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnumClassZeroBasedEnum.cs
index 2b062a550ab..cb6f10e40b3 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnumClassZeroBasedEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnumClassZeroBasedEnum.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnumClassZeroBasedEnum zeroBasedEnumClassZeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnumClassZeroBasedEnum.ToString());
+            writer.WriteStringValue(ZeroBasedEnumClassZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnumClassZeroBasedEnum).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the ZeroBasedEnumClassZeroBasedEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="zeroBasedEnumClassZeroBasedEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnumClassZeroBasedEnum? zeroBasedEnumClassZeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnumClassZeroBasedEnum?.ToString() ?? "null");
+            writer.WriteStringValue(zeroBasedEnumClassZeroBasedEnum.HasValue ? ZeroBasedEnumClassZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnumClassZeroBasedEnum.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/EnumClass.cs b/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/EnumClass.cs
index b1aff0adf0d..cefbf28588f 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/EnumClass.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/EnumClass.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass.ToString());
+            writer.WriteStringValue(EnumClassValueConverter.ToJsonValue(enumClass).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumClass to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumClass"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass? enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass?.ToString() ?? "null");
+            writer.WriteStringValue(enumClass.HasValue ? EnumClassValueConverter.ToJsonValue(enumClass.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/OuterEnum.cs b/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/OuterEnum.cs
index 47bb6793c6a..e72ea52b087 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/OuterEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/OuterEnum.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnum outerEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnum.ToString());
+            writer.WriteStringValue(OuterEnumValueConverter.ToJsonValue(outerEnum).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnum? outerEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnum?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnum.HasValue ? OuterEnumValueConverter.ToJsonValue(outerEnum.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs b/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
index 136fb4c54c4..e2c52f962f3 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumDefaultValue outerEnumDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumDefaultValue.ToString());
+            writer.WriteStringValue(OuterEnumDefaultValueValueConverter.ToJsonValue(outerEnumDefaultValue).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumDefaultValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumDefaultValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumDefaultValue? outerEnumDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumDefaultValue?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumDefaultValue.HasValue ? OuterEnumDefaultValueValueConverter.ToJsonValue(outerEnumDefaultValue.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/OuterEnumInteger.cs b/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
index 2ed4f18a657..e3812cb3198 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
@@ -135,7 +135,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumInteger outerEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumInteger.ToString());
+            writer.WriteStringValue(OuterEnumIntegerValueConverter.ToJsonValue(outerEnumInteger).ToString());
         }
     }
 
@@ -166,14 +166,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumInteger to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumInteger"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumInteger? outerEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumInteger?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumInteger.HasValue ? OuterEnumIntegerValueConverter.ToJsonValue(outerEnumInteger.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs b/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
index c6a470cc64d..296151997b0 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
@@ -135,7 +135,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumIntegerDefaultValue outerEnumIntegerDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumIntegerDefaultValue.ToString());
+            writer.WriteStringValue(OuterEnumIntegerDefaultValueValueConverter.ToJsonValue(outerEnumIntegerDefaultValue).ToString());
         }
     }
 
@@ -166,14 +166,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumIntegerDefaultValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumIntegerDefaultValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumIntegerDefaultValue? outerEnumIntegerDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumIntegerDefaultValue?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumIntegerDefaultValue.HasValue ? OuterEnumIntegerDefaultValueValueConverter.ToJsonValue(outerEnumIntegerDefaultValue.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/OuterEnumTest.cs b/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/OuterEnumTest.cs
index a2e789f2ede..b4c4e25a9bb 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/OuterEnumTest.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/OuterEnumTest.cs
@@ -214,7 +214,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumTest outerEnumTest, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumTest.ToString());
+            writer.WriteStringValue(OuterEnumTestValueConverter.ToJsonValue(outerEnumTest).ToString());
         }
     }
 
@@ -245,14 +245,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumTest to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumTest"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumTest? outerEnumTest, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumTest?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumTest.HasValue ? OuterEnumTestValueConverter.ToJsonValue(outerEnumTest.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/TestResultCode.cs b/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/TestResultCode.cs
index 0fc06c04a67..280c9b82cfa 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/TestResultCode.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/TestResultCode.cs
@@ -131,7 +131,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestResultCode testResultCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testResultCode.ToString());
+            writer.WriteStringValue(TestResultCodeValueConverter.ToJsonValue(testResultCode).ToString());
         }
     }
 
@@ -162,14 +162,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestResultCode to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testResultCode"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestResultCode? testResultCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testResultCode?.ToString() ?? "null");
+            writer.WriteStringValue(testResultCode.HasValue ? TestResultCodeValueConverter.ToJsonValue(testResultCode.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs b/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
index 34a044fb8b1..b82155f7800 100644
--- a/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net4.8/Petstore/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnum zeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnum.ToString());
+            writer.WriteStringValue(ZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnum).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the ZeroBasedEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="zeroBasedEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnum? zeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnum?.ToString() ?? "null");
+            writer.WriteStringValue(zeroBasedEnum.HasValue ? ZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnum.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/ChildCatAllOfPetType.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/ChildCatAllOfPetType.cs
index 9e8bc253fdb..252a51260bc 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/ChildCatAllOfPetType.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/ChildCatAllOfPetType.cs
@@ -116,7 +116,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ChildCatAllOfPetType childCatAllOfPetType, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(childCatAllOfPetType.ToString());
+            writer.WriteStringValue(ChildCatAllOfPetTypeValueConverter.ToJsonValue(childCatAllOfPetType).ToString());
         }
     }
 
@@ -147,14 +147,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the ChildCatAllOfPetType to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="childCatAllOfPetType"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ChildCatAllOfPetType? childCatAllOfPetType, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(childCatAllOfPetType?.ToString() ?? "null");
+            writer.WriteStringValue(childCatAllOfPetType.HasValue ? ChildCatAllOfPetTypeValueConverter.ToJsonValue(childCatAllOfPetType.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/EnumArraysArrayEnumInner.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/EnumArraysArrayEnumInner.cs
index c620b7197c4..2ceb96620d0 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/EnumArraysArrayEnumInner.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/EnumArraysArrayEnumInner.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumArraysArrayEnumInner enumArraysArrayEnumInner, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumArraysArrayEnumInner.ToString());
+            writer.WriteStringValue(EnumArraysArrayEnumInnerValueConverter.ToJsonValue(enumArraysArrayEnumInner).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumArraysArrayEnumInner to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumArraysArrayEnumInner"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumArraysArrayEnumInner? enumArraysArrayEnumInner, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumArraysArrayEnumInner?.ToString() ?? "null");
+            writer.WriteStringValue(enumArraysArrayEnumInner.HasValue ? EnumArraysArrayEnumInnerValueConverter.ToJsonValue(enumArraysArrayEnumInner.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/EnumArraysJustSymbol.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/EnumArraysJustSymbol.cs
index 4a414d11d0d..8400d5cd427 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/EnumArraysJustSymbol.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/EnumArraysJustSymbol.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumArraysJustSymbol enumArraysJustSymbol, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumArraysJustSymbol.ToString());
+            writer.WriteStringValue(EnumArraysJustSymbolValueConverter.ToJsonValue(enumArraysJustSymbol).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumArraysJustSymbol to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumArraysJustSymbol"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumArraysJustSymbol? enumArraysJustSymbol, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumArraysJustSymbol?.ToString() ?? "null");
+            writer.WriteStringValue(enumArraysJustSymbol.HasValue ? EnumArraysJustSymbolValueConverter.ToJsonValue(enumArraysJustSymbol.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/EnumClass.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/EnumClass.cs
index b1aff0adf0d..cefbf28588f 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/EnumClass.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/EnumClass.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass.ToString());
+            writer.WriteStringValue(EnumClassValueConverter.ToJsonValue(enumClass).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumClass to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumClass"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass? enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass?.ToString() ?? "null");
+            writer.WriteStringValue(enumClass.HasValue ? EnumClassValueConverter.ToJsonValue(enumClass.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumInteger.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumInteger.cs
index 3a1302bf271..19178ecba28 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumInteger.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumInteger.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumInteger enumTestEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumInteger.ToString());
+            writer.WriteStringValue(EnumTestEnumIntegerValueConverter.ToJsonValue(enumTestEnumInteger).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumTestEnumInteger to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumTestEnumInteger"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumInteger? enumTestEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumInteger?.ToString() ?? "null");
+            writer.WriteStringValue(enumTestEnumInteger.HasValue ? EnumTestEnumIntegerValueConverter.ToJsonValue(enumTestEnumInteger.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumIntegerOnly.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumIntegerOnly.cs
index cd0add6cf3c..6a999c69d57 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumIntegerOnly.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumIntegerOnly.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumIntegerOnly enumTestEnumIntegerOnly, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumIntegerOnly.ToString());
+            writer.WriteStringValue(EnumTestEnumIntegerOnlyValueConverter.ToJsonValue(enumTestEnumIntegerOnly).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumTestEnumIntegerOnly to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumTestEnumIntegerOnly"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumIntegerOnly? enumTestEnumIntegerOnly, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumIntegerOnly?.ToString() ?? "null");
+            writer.WriteStringValue(enumTestEnumIntegerOnly.HasValue ? EnumTestEnumIntegerOnlyValueConverter.ToJsonValue(enumTestEnumIntegerOnly.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumString.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumString.cs
index adad28355b7..4d02eeaec01 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumString.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumString.cs
@@ -214,7 +214,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumString enumTestEnumString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumString.ToString());
+            writer.WriteStringValue(EnumTestEnumStringValueConverter.ToJsonValue(enumTestEnumString).ToString());
         }
     }
 
@@ -245,14 +245,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumTestEnumString to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumTestEnumString"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumString? enumTestEnumString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumString?.ToString() ?? "null");
+            writer.WriteStringValue(enumTestEnumString.HasValue ? EnumTestEnumStringValueConverter.ToJsonValue(enumTestEnumString.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/FindPetsByStatusStatusParameterInner.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/FindPetsByStatusStatusParameterInner.cs
index da357d93dd2..e7f98f931cc 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/FindPetsByStatusStatusParameterInner.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/FindPetsByStatusStatusParameterInner.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, FindPetsByStatusStatusParameterInner findPetsByStatusStatusParameterInner, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(findPetsByStatusStatusParameterInner.ToString());
+            writer.WriteStringValue(FindPetsByStatusStatusParameterInnerValueConverter.ToJsonValue(findPetsByStatusStatusParameterInner).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the FindPetsByStatusStatusParameterInner to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="findPetsByStatusStatusParameterInner"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, FindPetsByStatusStatusParameterInner? findPetsByStatusStatusParameterInner, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(findPetsByStatusStatusParameterInner?.ToString() ?? "null");
+            writer.WriteStringValue(findPetsByStatusStatusParameterInner.HasValue ? FindPetsByStatusStatusParameterInnerValueConverter.ToJsonValue(findPetsByStatusStatusParameterInner.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/MapTestMapOfEnumStringValue.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/MapTestMapOfEnumStringValue.cs
index 441ea5dcb7d..3c7331f80f2 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/MapTestMapOfEnumStringValue.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/MapTestMapOfEnumStringValue.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, MapTestMapOfEnumStringValue mapTestMapOfEnumStringValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(mapTestMapOfEnumStringValue.ToString());
+            writer.WriteStringValue(MapTestMapOfEnumStringValueValueConverter.ToJsonValue(mapTestMapOfEnumStringValue).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the MapTestMapOfEnumStringValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="mapTestMapOfEnumStringValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, MapTestMapOfEnumStringValue? mapTestMapOfEnumStringValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(mapTestMapOfEnumStringValue?.ToString() ?? "null");
+            writer.WriteStringValue(mapTestMapOfEnumStringValue.HasValue ? MapTestMapOfEnumStringValueValueConverter.ToJsonValue(mapTestMapOfEnumStringValue.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/OrderStatus.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/OrderStatus.cs
index 6566ca4aa56..cd0ff06ce52 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/OrderStatus.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/OrderStatus.cs
@@ -145,7 +145,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OrderStatus orderStatus, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(orderStatus.ToString());
+            writer.WriteStringValue(OrderStatusValueConverter.ToJsonValue(orderStatus).ToString());
         }
     }
 
@@ -176,14 +176,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OrderStatus to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="orderStatus"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OrderStatus? orderStatus, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(orderStatus?.ToString() ?? "null");
+            writer.WriteStringValue(orderStatus.HasValue ? OrderStatusValueConverter.ToJsonValue(orderStatus.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/OuterEnum.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/OuterEnum.cs
index 47bb6793c6a..e72ea52b087 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/OuterEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/OuterEnum.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnum outerEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnum.ToString());
+            writer.WriteStringValue(OuterEnumValueConverter.ToJsonValue(outerEnum).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnum? outerEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnum?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnum.HasValue ? OuterEnumValueConverter.ToJsonValue(outerEnum.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
index 136fb4c54c4..e2c52f962f3 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumDefaultValue outerEnumDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumDefaultValue.ToString());
+            writer.WriteStringValue(OuterEnumDefaultValueValueConverter.ToJsonValue(outerEnumDefaultValue).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumDefaultValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumDefaultValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumDefaultValue? outerEnumDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumDefaultValue?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumDefaultValue.HasValue ? OuterEnumDefaultValueValueConverter.ToJsonValue(outerEnumDefaultValue.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/OuterEnumInteger.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
index 2ed4f18a657..e3812cb3198 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
@@ -135,7 +135,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumInteger outerEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumInteger.ToString());
+            writer.WriteStringValue(OuterEnumIntegerValueConverter.ToJsonValue(outerEnumInteger).ToString());
         }
     }
 
@@ -166,14 +166,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumInteger to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumInteger"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumInteger? outerEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumInteger?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumInteger.HasValue ? OuterEnumIntegerValueConverter.ToJsonValue(outerEnumInteger.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
index c6a470cc64d..296151997b0 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
@@ -135,7 +135,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumIntegerDefaultValue outerEnumIntegerDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumIntegerDefaultValue.ToString());
+            writer.WriteStringValue(OuterEnumIntegerDefaultValueValueConverter.ToJsonValue(outerEnumIntegerDefaultValue).ToString());
         }
     }
 
@@ -166,14 +166,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumIntegerDefaultValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumIntegerDefaultValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumIntegerDefaultValue? outerEnumIntegerDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumIntegerDefaultValue?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumIntegerDefaultValue.HasValue ? OuterEnumIntegerDefaultValueValueConverter.ToJsonValue(outerEnumIntegerDefaultValue.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/OuterEnumTest.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/OuterEnumTest.cs
index a2e789f2ede..b4c4e25a9bb 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/OuterEnumTest.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/OuterEnumTest.cs
@@ -214,7 +214,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumTest outerEnumTest, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumTest.ToString());
+            writer.WriteStringValue(OuterEnumTestValueConverter.ToJsonValue(outerEnumTest).ToString());
         }
     }
 
@@ -245,14 +245,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumTest to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumTest"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumTest? outerEnumTest, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumTest?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumTest.HasValue ? OuterEnumTestValueConverter.ToJsonValue(outerEnumTest.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/PetStatus.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/PetStatus.cs
index 9e19b612bf9..52de1419c80 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/PetStatus.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/PetStatus.cs
@@ -145,7 +145,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, PetStatus petStatus, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(petStatus.ToString());
+            writer.WriteStringValue(PetStatusValueConverter.ToJsonValue(petStatus).ToString());
         }
     }
 
@@ -176,14 +176,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the PetStatus to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="petStatus"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, PetStatus? petStatus, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(petStatus?.ToString() ?? "null");
+            writer.WriteStringValue(petStatus.HasValue ? PetStatusValueConverter.ToJsonValue(petStatus.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumInteger.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumInteger.cs
index 04988ef3ee9..fcdc5507481 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumInteger.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumInteger.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNotnullableEnumInteger requiredClassRequiredNotnullableEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNotnullableEnumInteger.ToString());
+            writer.WriteStringValue(RequiredClassRequiredNotnullableEnumIntegerValueConverter.ToJsonValue(requiredClassRequiredNotnullableEnumInteger).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the RequiredClassRequiredNotnullableEnumInteger to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="requiredClassRequiredNotnullableEnumInteger"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNotnullableEnumInteger? requiredClassRequiredNotnullableEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNotnullableEnumInteger?.ToString() ?? "null");
+            writer.WriteStringValue(requiredClassRequiredNotnullableEnumInteger.HasValue ? RequiredClassRequiredNotnullableEnumIntegerValueConverter.ToJsonValue(requiredClassRequiredNotnullableEnumInteger.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumIntegerOnly.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumIntegerOnly.cs
index 775aba4f6af..1d33399c633 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumIntegerOnly.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumIntegerOnly.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNotnullableEnumIntegerOnly requiredClassRequiredNotnullableEnumIntegerOnly, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNotnullableEnumIntegerOnly.ToString());
+            writer.WriteStringValue(RequiredClassRequiredNotnullableEnumIntegerOnlyValueConverter.ToJsonValue(requiredClassRequiredNotnullableEnumIntegerOnly).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the RequiredClassRequiredNotnullableEnumIntegerOnly to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="requiredClassRequiredNotnullableEnumIntegerOnly"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNotnullableEnumIntegerOnly? requiredClassRequiredNotnullableEnumIntegerOnly, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNotnullableEnumIntegerOnly?.ToString() ?? "null");
+            writer.WriteStringValue(requiredClassRequiredNotnullableEnumIntegerOnly.HasValue ? RequiredClassRequiredNotnullableEnumIntegerOnlyValueConverter.ToJsonValue(requiredClassRequiredNotnullableEnumIntegerOnly.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumString.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumString.cs
index 5b4f29294ac..1e251fee921 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumString.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumString.cs
@@ -214,7 +214,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNotnullableEnumString requiredClassRequiredNotnullableEnumString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNotnullableEnumString.ToString());
+            writer.WriteStringValue(RequiredClassRequiredNotnullableEnumStringValueConverter.ToJsonValue(requiredClassRequiredNotnullableEnumString).ToString());
         }
     }
 
@@ -245,14 +245,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the RequiredClassRequiredNotnullableEnumString to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="requiredClassRequiredNotnullableEnumString"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNotnullableEnumString? requiredClassRequiredNotnullableEnumString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNotnullableEnumString?.ToString() ?? "null");
+            writer.WriteStringValue(requiredClassRequiredNotnullableEnumString.HasValue ? RequiredClassRequiredNotnullableEnumStringValueConverter.ToJsonValue(requiredClassRequiredNotnullableEnumString.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumInteger.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumInteger.cs
index 365504a241b..97db2037f95 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumInteger.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumInteger.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNullableEnumInteger requiredClassRequiredNullableEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNullableEnumInteger.ToString());
+            writer.WriteStringValue(RequiredClassRequiredNullableEnumIntegerValueConverter.ToJsonValue(requiredClassRequiredNullableEnumInteger).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the RequiredClassRequiredNullableEnumInteger to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="requiredClassRequiredNullableEnumInteger"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNullableEnumInteger? requiredClassRequiredNullableEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNullableEnumInteger?.ToString() ?? "null");
+            writer.WriteStringValue(requiredClassRequiredNullableEnumInteger.HasValue ? RequiredClassRequiredNullableEnumIntegerValueConverter.ToJsonValue(requiredClassRequiredNullableEnumInteger.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumIntegerOnly.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumIntegerOnly.cs
index 4c5f2c56ba5..2f53261cd6f 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumIntegerOnly.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumIntegerOnly.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNullableEnumIntegerOnly requiredClassRequiredNullableEnumIntegerOnly, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNullableEnumIntegerOnly.ToString());
+            writer.WriteStringValue(RequiredClassRequiredNullableEnumIntegerOnlyValueConverter.ToJsonValue(requiredClassRequiredNullableEnumIntegerOnly).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the RequiredClassRequiredNullableEnumIntegerOnly to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="requiredClassRequiredNullableEnumIntegerOnly"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNullableEnumIntegerOnly? requiredClassRequiredNullableEnumIntegerOnly, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNullableEnumIntegerOnly?.ToString() ?? "null");
+            writer.WriteStringValue(requiredClassRequiredNullableEnumIntegerOnly.HasValue ? RequiredClassRequiredNullableEnumIntegerOnlyValueConverter.ToJsonValue(requiredClassRequiredNullableEnumIntegerOnly.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumString.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumString.cs
index 36bcb148131..7efe892e924 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumString.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumString.cs
@@ -214,7 +214,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNullableEnumString requiredClassRequiredNullableEnumString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNullableEnumString.ToString());
+            writer.WriteStringValue(RequiredClassRequiredNullableEnumStringValueConverter.ToJsonValue(requiredClassRequiredNullableEnumString).ToString());
         }
     }
 
@@ -245,14 +245,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the RequiredClassRequiredNullableEnumString to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="requiredClassRequiredNullableEnumString"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNullableEnumString? requiredClassRequiredNullableEnumString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNullableEnumString?.ToString() ?? "null");
+            writer.WriteStringValue(requiredClassRequiredNullableEnumString.HasValue ? RequiredClassRequiredNullableEnumStringValueConverter.ToJsonValue(requiredClassRequiredNullableEnumString.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestDescendantsObjectType.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestDescendantsObjectType.cs
index 32fdf9b1c3b..0c0c757cc59 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestDescendantsObjectType.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestDescendantsObjectType.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestDescendantsObjectType testDescendantsObjectType, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testDescendantsObjectType.ToString());
+            writer.WriteStringValue(TestDescendantsObjectTypeValueConverter.ToJsonValue(testDescendantsObjectType).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestDescendantsObjectType to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testDescendantsObjectType"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestDescendantsObjectType? testDescendantsObjectType, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testDescendantsObjectType?.ToString() ?? "null");
+            writer.WriteStringValue(testDescendantsObjectType.HasValue ? TestDescendantsObjectTypeValueConverter.ToJsonValue(testDescendantsObjectType.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumHeaderStringParameter.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumHeaderStringParameter.cs
index ccb446b0250..4fe8d2deb70 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumHeaderStringParameter.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumHeaderStringParameter.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersEnumHeaderStringParameter testEnumParametersEnumHeaderStringParameter, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersEnumHeaderStringParameter.ToString());
+            writer.WriteStringValue(TestEnumParametersEnumHeaderStringParameterValueConverter.ToJsonValue(testEnumParametersEnumHeaderStringParameter).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestEnumParametersEnumHeaderStringParameter to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testEnumParametersEnumHeaderStringParameter"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersEnumHeaderStringParameter? testEnumParametersEnumHeaderStringParameter, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersEnumHeaderStringParameter?.ToString() ?? "null");
+            writer.WriteStringValue(testEnumParametersEnumHeaderStringParameter.HasValue ? TestEnumParametersEnumHeaderStringParameterValueConverter.ToJsonValue(testEnumParametersEnumHeaderStringParameter.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryDoubleParameter.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryDoubleParameter.cs
index ec14b39944d..d4d97e76043 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryDoubleParameter.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryDoubleParameter.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersEnumQueryDoubleParameter testEnumParametersEnumQueryDoubleParameter, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersEnumQueryDoubleParameter.ToString());
+            writer.WriteStringValue(TestEnumParametersEnumQueryDoubleParameterValueConverter.ToJsonValue(testEnumParametersEnumQueryDoubleParameter).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestEnumParametersEnumQueryDoubleParameter to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testEnumParametersEnumQueryDoubleParameter"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersEnumQueryDoubleParameter? testEnumParametersEnumQueryDoubleParameter, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersEnumQueryDoubleParameter?.ToString() ?? "null");
+            writer.WriteStringValue(testEnumParametersEnumQueryDoubleParameter.HasValue ? TestEnumParametersEnumQueryDoubleParameterValueConverter.ToJsonValue(testEnumParametersEnumQueryDoubleParameter.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryIntegerParameter.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryIntegerParameter.cs
index 33ff2ce2cc2..85149c3f5eb 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryIntegerParameter.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryIntegerParameter.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersEnumQueryIntegerParameter testEnumParametersEnumQueryIntegerParameter, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersEnumQueryIntegerParameter.ToString());
+            writer.WriteStringValue(TestEnumParametersEnumQueryIntegerParameterValueConverter.ToJsonValue(testEnumParametersEnumQueryIntegerParameter).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestEnumParametersEnumQueryIntegerParameter to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testEnumParametersEnumQueryIntegerParameter"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersEnumQueryIntegerParameter? testEnumParametersEnumQueryIntegerParameter, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersEnumQueryIntegerParameter?.ToString() ?? "null");
+            writer.WriteStringValue(testEnumParametersEnumQueryIntegerParameter.HasValue ? TestEnumParametersEnumQueryIntegerParameterValueConverter.ToJsonValue(testEnumParametersEnumQueryIntegerParameter.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormString.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormString.cs
index d86b48d4a9b..2e81a11c33b 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormString.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormString.cs
@@ -145,7 +145,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersRequestEnumFormString testEnumParametersRequestEnumFormString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersRequestEnumFormString.ToString());
+            writer.WriteStringValue(TestEnumParametersRequestEnumFormStringValueConverter.ToJsonValue(testEnumParametersRequestEnumFormString).ToString());
         }
     }
 
@@ -176,14 +176,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestEnumParametersRequestEnumFormString to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testEnumParametersRequestEnumFormString"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersRequestEnumFormString? testEnumParametersRequestEnumFormString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersRequestEnumFormString?.ToString() ?? "null");
+            writer.WriteStringValue(testEnumParametersRequestEnumFormString.HasValue ? TestEnumParametersRequestEnumFormStringValueConverter.ToJsonValue(testEnumParametersRequestEnumFormString.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormStringArrayInner.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormStringArrayInner.cs
index 4f1c9c53c60..5c00030c30a 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormStringArrayInner.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormStringArrayInner.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersRequestEnumFormStringArrayInner testEnumParametersRequestEnumFormStringArrayInner, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersRequestEnumFormStringArrayInner.ToString());
+            writer.WriteStringValue(TestEnumParametersRequestEnumFormStringArrayInnerValueConverter.ToJsonValue(testEnumParametersRequestEnumFormStringArrayInner).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestEnumParametersRequestEnumFormStringArrayInner to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testEnumParametersRequestEnumFormStringArrayInner"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersRequestEnumFormStringArrayInner? testEnumParametersRequestEnumFormStringArrayInner, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersRequestEnumFormStringArrayInner?.ToString() ?? "null");
+            writer.WriteStringValue(testEnumParametersRequestEnumFormStringArrayInner.HasValue ? TestEnumParametersRequestEnumFormStringArrayInnerValueConverter.ToJsonValue(testEnumParametersRequestEnumFormStringArrayInner.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestResultCode.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestResultCode.cs
index 0fc06c04a67..280c9b82cfa 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestResultCode.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/TestResultCode.cs
@@ -131,7 +131,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestResultCode testResultCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testResultCode.ToString());
+            writer.WriteStringValue(TestResultCodeValueConverter.ToJsonValue(testResultCode).ToString());
         }
     }
 
@@ -162,14 +162,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestResultCode to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testResultCode"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestResultCode? testResultCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testResultCode?.ToString() ?? "null");
+            writer.WriteStringValue(testResultCode.HasValue ? TestResultCodeValueConverter.ToJsonValue(testResultCode.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/ZebraType.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/ZebraType.cs
index 4a54f2a265a..5eb8d6bac71 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/ZebraType.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/ZebraType.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZebraType zebraType, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zebraType.ToString());
+            writer.WriteStringValue(ZebraTypeValueConverter.ToJsonValue(zebraType).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the ZebraType to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="zebraType"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZebraType? zebraType, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zebraType?.ToString() ?? "null");
+            writer.WriteStringValue(zebraType.HasValue ? ZebraTypeValueConverter.ToJsonValue(zebraType.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
index 34a044fb8b1..b82155f7800 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnum zeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnum.ToString());
+            writer.WriteStringValue(ZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnum).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the ZeroBasedEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="zeroBasedEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnum? zeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnum?.ToString() ?? "null");
+            writer.WriteStringValue(zeroBasedEnum.HasValue ? ZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnum.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnumClassZeroBasedEnum.cs b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnumClassZeroBasedEnum.cs
index 2b062a550ab..cb6f10e40b3 100644
--- a/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnumClassZeroBasedEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net8/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnumClassZeroBasedEnum.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnumClassZeroBasedEnum zeroBasedEnumClassZeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnumClassZeroBasedEnum.ToString());
+            writer.WriteStringValue(ZeroBasedEnumClassZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnumClassZeroBasedEnum).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the ZeroBasedEnumClassZeroBasedEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="zeroBasedEnumClassZeroBasedEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnumClassZeroBasedEnum? zeroBasedEnumClassZeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnumClassZeroBasedEnum?.ToString() ?? "null");
+            writer.WriteStringValue(zeroBasedEnumClassZeroBasedEnum.HasValue ? ZeroBasedEnumClassZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnumClassZeroBasedEnum.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/ManualPetstoreTests/OpenAPIClient-generichost-manual-tests/UnitTest1.cs b/samples/client/petstore/csharp/generichost/net8/ManualPetstoreTests/OpenAPIClient-generichost-manual-tests/UnitTest1.cs
index eba2904f0bd..a67d6eb2b3f 100644
--- a/samples/client/petstore/csharp/generichost/net8/ManualPetstoreTests/OpenAPIClient-generichost-manual-tests/UnitTest1.cs
+++ b/samples/client/petstore/csharp/generichost/net8/ManualPetstoreTests/OpenAPIClient-generichost-manual-tests/UnitTest1.cs
@@ -189,5 +189,14 @@ namespace OpenAPIClient_generichost_manual_tests
             string result = JsonSerializer.Serialize(animal, _jsonSerializerOptions);
             Assert.AreEqual(expected, result);
         }
+
+        [TestMethod]
+        public void Enum() {
+            string expected = """["_abc","-efg","(xyz)"]""";
+            List<EnumClass?>? enumClasses = JsonSerializer.Deserialize<List<EnumClass?>>(expected, _jsonSerializerOptions);
+            Assert.IsNotNull(enumClasses);
+            string result = JsonSerializer.Serialize(enumClasses, _jsonSerializerOptions);
+            Assert.AreEqual(expected, result);
+        }
     }
 }
\ No newline at end of file
diff --git a/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/EnumClass.cs b/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/EnumClass.cs
index 03b2780c484..592f6a59c31 100644
--- a/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/EnumClass.cs
+++ b/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/EnumClass.cs
@@ -146,7 +146,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass.ToString());
+            writer.WriteStringValue(EnumClassValueConverter.ToJsonValue(enumClass).ToString());
         }
     }
 
@@ -177,14 +177,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumClass to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumClass"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass? enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass?.ToString() ?? "null");
+            writer.WriteStringValue(enumClass.HasValue ? EnumClassValueConverter.ToJsonValue(enumClass.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnum.cs b/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnum.cs
index 96af6f3670d..0476c873cd8 100644
--- a/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnum.cs
@@ -146,7 +146,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnum outerEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnum.ToString());
+            writer.WriteStringValue(OuterEnumValueConverter.ToJsonValue(outerEnum).ToString());
         }
     }
 
@@ -177,14 +177,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnum? outerEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnum?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnum.HasValue ? OuterEnumValueConverter.ToJsonValue(outerEnum.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs b/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
index a50d5c056ec..68faa3cd5de 100644
--- a/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
+++ b/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
@@ -146,7 +146,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumDefaultValue outerEnumDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumDefaultValue.ToString());
+            writer.WriteStringValue(OuterEnumDefaultValueValueConverter.ToJsonValue(outerEnumDefaultValue).ToString());
         }
     }
 
@@ -177,14 +177,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumDefaultValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumDefaultValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumDefaultValue? outerEnumDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumDefaultValue?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumDefaultValue.HasValue ? OuterEnumDefaultValueValueConverter.ToJsonValue(outerEnumDefaultValue.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumInteger.cs b/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
index 41ecebcf8f5..6ba997e06eb 100644
--- a/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
+++ b/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
@@ -137,7 +137,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumInteger outerEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumInteger.ToString());
+            writer.WriteStringValue(OuterEnumIntegerValueConverter.ToJsonValue(outerEnumInteger).ToString());
         }
     }
 
@@ -168,14 +168,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumInteger to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumInteger"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumInteger? outerEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumInteger?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumInteger.HasValue ? OuterEnumIntegerValueConverter.ToJsonValue(outerEnumInteger.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs b/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
index 902dbb06639..d8d27e54ee3 100644
--- a/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
+++ b/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
@@ -137,7 +137,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumIntegerDefaultValue outerEnumIntegerDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumIntegerDefaultValue.ToString());
+            writer.WriteStringValue(OuterEnumIntegerDefaultValueValueConverter.ToJsonValue(outerEnumIntegerDefaultValue).ToString());
         }
     }
 
@@ -168,14 +168,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumIntegerDefaultValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumIntegerDefaultValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumIntegerDefaultValue? outerEnumIntegerDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumIntegerDefaultValue?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumIntegerDefaultValue.HasValue ? OuterEnumIntegerDefaultValueValueConverter.ToJsonValue(outerEnumIntegerDefaultValue.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumTest.cs b/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumTest.cs
index 03a8ccdecac..5a1f2a6e439 100644
--- a/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumTest.cs
+++ b/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumTest.cs
@@ -216,7 +216,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumTest outerEnumTest, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumTest.ToString());
+            writer.WriteStringValue(OuterEnumTestValueConverter.ToJsonValue(outerEnumTest).ToString());
         }
     }
 
@@ -247,14 +247,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumTest to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumTest"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumTest? outerEnumTest, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumTest?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumTest.HasValue ? OuterEnumTestValueConverter.ToJsonValue(outerEnumTest.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/TestResultCode.cs b/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/TestResultCode.cs
index 2523ba0414a..f53e8d34214 100644
--- a/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/TestResultCode.cs
+++ b/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/TestResultCode.cs
@@ -133,7 +133,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestResultCode testResultCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testResultCode.ToString());
+            writer.WriteStringValue(TestResultCodeValueConverter.ToJsonValue(testResultCode).ToString());
         }
     }
 
@@ -164,14 +164,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestResultCode to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testResultCode"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestResultCode? testResultCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testResultCode?.ToString() ?? "null");
+            writer.WriteStringValue(testResultCode.HasValue ? TestResultCodeValueConverter.ToJsonValue(testResultCode.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs b/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
index 1db14d35a9e..5434f2b84ea 100644
--- a/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
@@ -132,7 +132,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnum zeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnum.ToString());
+            writer.WriteStringValue(ZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnum).ToString());
         }
     }
 
@@ -163,14 +163,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the ZeroBasedEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="zeroBasedEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnum? zeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnum?.ToString() ?? "null");
+            writer.WriteStringValue(zeroBasedEnum.HasValue ? ZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnum.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/EnumClass.cs b/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/EnumClass.cs
index b1aff0adf0d..cefbf28588f 100644
--- a/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/EnumClass.cs
+++ b/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/EnumClass.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass.ToString());
+            writer.WriteStringValue(EnumClassValueConverter.ToJsonValue(enumClass).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumClass to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumClass"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass? enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass?.ToString() ?? "null");
+            writer.WriteStringValue(enumClass.HasValue ? EnumClassValueConverter.ToJsonValue(enumClass.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/OuterEnum.cs b/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/OuterEnum.cs
index 47bb6793c6a..e72ea52b087 100644
--- a/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/OuterEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/OuterEnum.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnum outerEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnum.ToString());
+            writer.WriteStringValue(OuterEnumValueConverter.ToJsonValue(outerEnum).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnum? outerEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnum?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnum.HasValue ? OuterEnumValueConverter.ToJsonValue(outerEnum.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs b/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
index 136fb4c54c4..e2c52f962f3 100644
--- a/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
+++ b/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumDefaultValue outerEnumDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumDefaultValue.ToString());
+            writer.WriteStringValue(OuterEnumDefaultValueValueConverter.ToJsonValue(outerEnumDefaultValue).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumDefaultValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumDefaultValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumDefaultValue? outerEnumDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumDefaultValue?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumDefaultValue.HasValue ? OuterEnumDefaultValueValueConverter.ToJsonValue(outerEnumDefaultValue.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/OuterEnumInteger.cs b/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
index 2ed4f18a657..e3812cb3198 100644
--- a/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
+++ b/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
@@ -135,7 +135,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumInteger outerEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumInteger.ToString());
+            writer.WriteStringValue(OuterEnumIntegerValueConverter.ToJsonValue(outerEnumInteger).ToString());
         }
     }
 
@@ -166,14 +166,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumInteger to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumInteger"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumInteger? outerEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumInteger?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumInteger.HasValue ? OuterEnumIntegerValueConverter.ToJsonValue(outerEnumInteger.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs b/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
index c6a470cc64d..296151997b0 100644
--- a/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
+++ b/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
@@ -135,7 +135,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumIntegerDefaultValue outerEnumIntegerDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumIntegerDefaultValue.ToString());
+            writer.WriteStringValue(OuterEnumIntegerDefaultValueValueConverter.ToJsonValue(outerEnumIntegerDefaultValue).ToString());
         }
     }
 
@@ -166,14 +166,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumIntegerDefaultValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumIntegerDefaultValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumIntegerDefaultValue? outerEnumIntegerDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumIntegerDefaultValue?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumIntegerDefaultValue.HasValue ? OuterEnumIntegerDefaultValueValueConverter.ToJsonValue(outerEnumIntegerDefaultValue.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/OuterEnumTest.cs b/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/OuterEnumTest.cs
index a2e789f2ede..b4c4e25a9bb 100644
--- a/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/OuterEnumTest.cs
+++ b/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/OuterEnumTest.cs
@@ -214,7 +214,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumTest outerEnumTest, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumTest.ToString());
+            writer.WriteStringValue(OuterEnumTestValueConverter.ToJsonValue(outerEnumTest).ToString());
         }
     }
 
@@ -245,14 +245,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumTest to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumTest"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumTest? outerEnumTest, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumTest?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumTest.HasValue ? OuterEnumTestValueConverter.ToJsonValue(outerEnumTest.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/TestResultCode.cs b/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/TestResultCode.cs
index 0fc06c04a67..280c9b82cfa 100644
--- a/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/TestResultCode.cs
+++ b/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/TestResultCode.cs
@@ -131,7 +131,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestResultCode testResultCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testResultCode.ToString());
+            writer.WriteStringValue(TestResultCodeValueConverter.ToJsonValue(testResultCode).ToString());
         }
     }
 
@@ -162,14 +162,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestResultCode to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testResultCode"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestResultCode? testResultCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testResultCode?.ToString() ?? "null");
+            writer.WriteStringValue(testResultCode.HasValue ? TestResultCodeValueConverter.ToJsonValue(testResultCode.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs b/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
index 34a044fb8b1..b82155f7800 100644
--- a/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net8/Petstore/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnum zeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnum.ToString());
+            writer.WriteStringValue(ZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnum).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the ZeroBasedEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="zeroBasedEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnum? zeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnum?.ToString() ?? "null");
+            writer.WriteStringValue(zeroBasedEnum.HasValue ? ZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnum.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/EnumClass.cs b/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/EnumClass.cs
index 520dc1cfbde..6192d15c9f5 100644
--- a/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/EnumClass.cs
+++ b/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/EnumClass.cs
@@ -147,7 +147,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass.ToString());
+            writer.WriteStringValue(EnumClassValueConverter.ToJsonValue(enumClass).ToString());
         }
     }
 
@@ -178,14 +178,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumClass to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumClass"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass? enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass?.ToString() ?? "null");
+            writer.WriteStringValue(enumClass.HasValue ? EnumClassValueConverter.ToJsonValue(enumClass.Value).ToString() : "null");
         }
     }
 
diff --git a/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnum.cs b/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnum.cs
index 803ca5e1771..c2b58fa0eba 100644
--- a/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnum.cs
@@ -147,7 +147,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnum outerEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnum.ToString());
+            writer.WriteStringValue(OuterEnumValueConverter.ToJsonValue(outerEnum).ToString());
         }
     }
 
@@ -178,14 +178,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnum? outerEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnum?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnum.HasValue ? OuterEnumValueConverter.ToJsonValue(outerEnum.Value).ToString() : "null");
         }
     }
 
diff --git a/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs b/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
index 1d30a9abb74..fa6acccc08e 100644
--- a/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
+++ b/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
@@ -147,7 +147,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumDefaultValue outerEnumDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumDefaultValue.ToString());
+            writer.WriteStringValue(OuterEnumDefaultValueValueConverter.ToJsonValue(outerEnumDefaultValue).ToString());
         }
     }
 
@@ -178,14 +178,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumDefaultValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumDefaultValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumDefaultValue? outerEnumDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumDefaultValue?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumDefaultValue.HasValue ? OuterEnumDefaultValueValueConverter.ToJsonValue(outerEnumDefaultValue.Value).ToString() : "null");
         }
     }
 
diff --git a/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumInteger.cs b/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
index 0d9bcfd0835..362553f662a 100644
--- a/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
+++ b/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
@@ -138,7 +138,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumInteger outerEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumInteger.ToString());
+            writer.WriteStringValue(OuterEnumIntegerValueConverter.ToJsonValue(outerEnumInteger).ToString());
         }
     }
 
@@ -169,14 +169,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumInteger to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumInteger"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumInteger? outerEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumInteger?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumInteger.HasValue ? OuterEnumIntegerValueConverter.ToJsonValue(outerEnumInteger.Value).ToString() : "null");
         }
     }
 
diff --git a/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs b/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
index b0d7b8ea075..fba1de8e6f3 100644
--- a/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
+++ b/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
@@ -138,7 +138,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumIntegerDefaultValue outerEnumIntegerDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumIntegerDefaultValue.ToString());
+            writer.WriteStringValue(OuterEnumIntegerDefaultValueValueConverter.ToJsonValue(outerEnumIntegerDefaultValue).ToString());
         }
     }
 
@@ -169,14 +169,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumIntegerDefaultValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumIntegerDefaultValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumIntegerDefaultValue? outerEnumIntegerDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumIntegerDefaultValue?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumIntegerDefaultValue.HasValue ? OuterEnumIntegerDefaultValueValueConverter.ToJsonValue(outerEnumIntegerDefaultValue.Value).ToString() : "null");
         }
     }
 
diff --git a/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumTest.cs b/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumTest.cs
index 56a81b57e54..b8716ad2b25 100644
--- a/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumTest.cs
+++ b/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumTest.cs
@@ -217,7 +217,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumTest outerEnumTest, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumTest.ToString());
+            writer.WriteStringValue(OuterEnumTestValueConverter.ToJsonValue(outerEnumTest).ToString());
         }
     }
 
@@ -248,14 +248,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumTest to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumTest"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumTest? outerEnumTest, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumTest?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumTest.HasValue ? OuterEnumTestValueConverter.ToJsonValue(outerEnumTest.Value).ToString() : "null");
         }
     }
 
diff --git a/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/TestResultCode.cs b/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/TestResultCode.cs
index 4d4a979a814..029a66af518 100644
--- a/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/TestResultCode.cs
+++ b/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/TestResultCode.cs
@@ -134,7 +134,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestResultCode testResultCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testResultCode.ToString());
+            writer.WriteStringValue(TestResultCodeValueConverter.ToJsonValue(testResultCode).ToString());
         }
     }
 
@@ -165,14 +165,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestResultCode to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testResultCode"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestResultCode? testResultCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testResultCode?.ToString() ?? "null");
+            writer.WriteStringValue(testResultCode.HasValue ? TestResultCodeValueConverter.ToJsonValue(testResultCode.Value).ToString() : "null");
         }
     }
 
diff --git a/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs b/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
index 15c22d0fc3b..c553e7d9ef5 100644
--- a/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net8/SourceGeneration/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
@@ -133,7 +133,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnum zeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnum.ToString());
+            writer.WriteStringValue(ZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnum).ToString());
         }
     }
 
@@ -164,14 +164,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the ZeroBasedEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="zeroBasedEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnum? zeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnum?.ToString() ?? "null");
+            writer.WriteStringValue(zeroBasedEnum.HasValue ? ZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnum.Value).ToString() : "null");
         }
     }
 
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/ChildCatAllOfPetType.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/ChildCatAllOfPetType.cs
index 9e8bc253fdb..252a51260bc 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/ChildCatAllOfPetType.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/ChildCatAllOfPetType.cs
@@ -116,7 +116,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ChildCatAllOfPetType childCatAllOfPetType, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(childCatAllOfPetType.ToString());
+            writer.WriteStringValue(ChildCatAllOfPetTypeValueConverter.ToJsonValue(childCatAllOfPetType).ToString());
         }
     }
 
@@ -147,14 +147,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the ChildCatAllOfPetType to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="childCatAllOfPetType"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ChildCatAllOfPetType? childCatAllOfPetType, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(childCatAllOfPetType?.ToString() ?? "null");
+            writer.WriteStringValue(childCatAllOfPetType.HasValue ? ChildCatAllOfPetTypeValueConverter.ToJsonValue(childCatAllOfPetType.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/EnumArraysArrayEnumInner.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/EnumArraysArrayEnumInner.cs
index c620b7197c4..2ceb96620d0 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/EnumArraysArrayEnumInner.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/EnumArraysArrayEnumInner.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumArraysArrayEnumInner enumArraysArrayEnumInner, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumArraysArrayEnumInner.ToString());
+            writer.WriteStringValue(EnumArraysArrayEnumInnerValueConverter.ToJsonValue(enumArraysArrayEnumInner).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumArraysArrayEnumInner to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumArraysArrayEnumInner"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumArraysArrayEnumInner? enumArraysArrayEnumInner, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumArraysArrayEnumInner?.ToString() ?? "null");
+            writer.WriteStringValue(enumArraysArrayEnumInner.HasValue ? EnumArraysArrayEnumInnerValueConverter.ToJsonValue(enumArraysArrayEnumInner.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/EnumArraysJustSymbol.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/EnumArraysJustSymbol.cs
index 4a414d11d0d..8400d5cd427 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/EnumArraysJustSymbol.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/EnumArraysJustSymbol.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumArraysJustSymbol enumArraysJustSymbol, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumArraysJustSymbol.ToString());
+            writer.WriteStringValue(EnumArraysJustSymbolValueConverter.ToJsonValue(enumArraysJustSymbol).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumArraysJustSymbol to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumArraysJustSymbol"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumArraysJustSymbol? enumArraysJustSymbol, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumArraysJustSymbol?.ToString() ?? "null");
+            writer.WriteStringValue(enumArraysJustSymbol.HasValue ? EnumArraysJustSymbolValueConverter.ToJsonValue(enumArraysJustSymbol.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/EnumClass.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/EnumClass.cs
index b1aff0adf0d..cefbf28588f 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/EnumClass.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/EnumClass.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass.ToString());
+            writer.WriteStringValue(EnumClassValueConverter.ToJsonValue(enumClass).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumClass to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumClass"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass? enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass?.ToString() ?? "null");
+            writer.WriteStringValue(enumClass.HasValue ? EnumClassValueConverter.ToJsonValue(enumClass.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumInteger.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumInteger.cs
index 3a1302bf271..19178ecba28 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumInteger.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumInteger.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumInteger enumTestEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumInteger.ToString());
+            writer.WriteStringValue(EnumTestEnumIntegerValueConverter.ToJsonValue(enumTestEnumInteger).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumTestEnumInteger to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumTestEnumInteger"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumInteger? enumTestEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumInteger?.ToString() ?? "null");
+            writer.WriteStringValue(enumTestEnumInteger.HasValue ? EnumTestEnumIntegerValueConverter.ToJsonValue(enumTestEnumInteger.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumIntegerOnly.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumIntegerOnly.cs
index cd0add6cf3c..6a999c69d57 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumIntegerOnly.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumIntegerOnly.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumIntegerOnly enumTestEnumIntegerOnly, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumIntegerOnly.ToString());
+            writer.WriteStringValue(EnumTestEnumIntegerOnlyValueConverter.ToJsonValue(enumTestEnumIntegerOnly).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumTestEnumIntegerOnly to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumTestEnumIntegerOnly"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumIntegerOnly? enumTestEnumIntegerOnly, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumIntegerOnly?.ToString() ?? "null");
+            writer.WriteStringValue(enumTestEnumIntegerOnly.HasValue ? EnumTestEnumIntegerOnlyValueConverter.ToJsonValue(enumTestEnumIntegerOnly.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumString.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumString.cs
index adad28355b7..4d02eeaec01 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumString.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/EnumTestEnumString.cs
@@ -214,7 +214,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumString enumTestEnumString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumString.ToString());
+            writer.WriteStringValue(EnumTestEnumStringValueConverter.ToJsonValue(enumTestEnumString).ToString());
         }
     }
 
@@ -245,14 +245,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumTestEnumString to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumTestEnumString"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumTestEnumString? enumTestEnumString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumTestEnumString?.ToString() ?? "null");
+            writer.WriteStringValue(enumTestEnumString.HasValue ? EnumTestEnumStringValueConverter.ToJsonValue(enumTestEnumString.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/FindPetsByStatusStatusParameterInner.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/FindPetsByStatusStatusParameterInner.cs
index da357d93dd2..e7f98f931cc 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/FindPetsByStatusStatusParameterInner.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/FindPetsByStatusStatusParameterInner.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, FindPetsByStatusStatusParameterInner findPetsByStatusStatusParameterInner, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(findPetsByStatusStatusParameterInner.ToString());
+            writer.WriteStringValue(FindPetsByStatusStatusParameterInnerValueConverter.ToJsonValue(findPetsByStatusStatusParameterInner).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the FindPetsByStatusStatusParameterInner to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="findPetsByStatusStatusParameterInner"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, FindPetsByStatusStatusParameterInner? findPetsByStatusStatusParameterInner, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(findPetsByStatusStatusParameterInner?.ToString() ?? "null");
+            writer.WriteStringValue(findPetsByStatusStatusParameterInner.HasValue ? FindPetsByStatusStatusParameterInnerValueConverter.ToJsonValue(findPetsByStatusStatusParameterInner.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/MapTestMapOfEnumStringValue.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/MapTestMapOfEnumStringValue.cs
index 441ea5dcb7d..3c7331f80f2 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/MapTestMapOfEnumStringValue.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/MapTestMapOfEnumStringValue.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, MapTestMapOfEnumStringValue mapTestMapOfEnumStringValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(mapTestMapOfEnumStringValue.ToString());
+            writer.WriteStringValue(MapTestMapOfEnumStringValueValueConverter.ToJsonValue(mapTestMapOfEnumStringValue).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the MapTestMapOfEnumStringValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="mapTestMapOfEnumStringValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, MapTestMapOfEnumStringValue? mapTestMapOfEnumStringValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(mapTestMapOfEnumStringValue?.ToString() ?? "null");
+            writer.WriteStringValue(mapTestMapOfEnumStringValue.HasValue ? MapTestMapOfEnumStringValueValueConverter.ToJsonValue(mapTestMapOfEnumStringValue.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/OrderStatus.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/OrderStatus.cs
index 6566ca4aa56..cd0ff06ce52 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/OrderStatus.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/OrderStatus.cs
@@ -145,7 +145,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OrderStatus orderStatus, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(orderStatus.ToString());
+            writer.WriteStringValue(OrderStatusValueConverter.ToJsonValue(orderStatus).ToString());
         }
     }
 
@@ -176,14 +176,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OrderStatus to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="orderStatus"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OrderStatus? orderStatus, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(orderStatus?.ToString() ?? "null");
+            writer.WriteStringValue(orderStatus.HasValue ? OrderStatusValueConverter.ToJsonValue(orderStatus.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/OuterEnum.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/OuterEnum.cs
index 47bb6793c6a..e72ea52b087 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/OuterEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/OuterEnum.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnum outerEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnum.ToString());
+            writer.WriteStringValue(OuterEnumValueConverter.ToJsonValue(outerEnum).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnum? outerEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnum?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnum.HasValue ? OuterEnumValueConverter.ToJsonValue(outerEnum.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
index 136fb4c54c4..e2c52f962f3 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumDefaultValue outerEnumDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumDefaultValue.ToString());
+            writer.WriteStringValue(OuterEnumDefaultValueValueConverter.ToJsonValue(outerEnumDefaultValue).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumDefaultValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumDefaultValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumDefaultValue? outerEnumDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumDefaultValue?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumDefaultValue.HasValue ? OuterEnumDefaultValueValueConverter.ToJsonValue(outerEnumDefaultValue.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/OuterEnumInteger.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
index 2ed4f18a657..e3812cb3198 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
@@ -135,7 +135,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumInteger outerEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumInteger.ToString());
+            writer.WriteStringValue(OuterEnumIntegerValueConverter.ToJsonValue(outerEnumInteger).ToString());
         }
     }
 
@@ -166,14 +166,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumInteger to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumInteger"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumInteger? outerEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumInteger?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumInteger.HasValue ? OuterEnumIntegerValueConverter.ToJsonValue(outerEnumInteger.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
index c6a470cc64d..296151997b0 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
@@ -135,7 +135,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumIntegerDefaultValue outerEnumIntegerDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumIntegerDefaultValue.ToString());
+            writer.WriteStringValue(OuterEnumIntegerDefaultValueValueConverter.ToJsonValue(outerEnumIntegerDefaultValue).ToString());
         }
     }
 
@@ -166,14 +166,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumIntegerDefaultValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumIntegerDefaultValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumIntegerDefaultValue? outerEnumIntegerDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumIntegerDefaultValue?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumIntegerDefaultValue.HasValue ? OuterEnumIntegerDefaultValueValueConverter.ToJsonValue(outerEnumIntegerDefaultValue.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/OuterEnumTest.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/OuterEnumTest.cs
index a2e789f2ede..b4c4e25a9bb 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/OuterEnumTest.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/OuterEnumTest.cs
@@ -214,7 +214,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumTest outerEnumTest, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumTest.ToString());
+            writer.WriteStringValue(OuterEnumTestValueConverter.ToJsonValue(outerEnumTest).ToString());
         }
     }
 
@@ -245,14 +245,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumTest to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumTest"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumTest? outerEnumTest, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumTest?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumTest.HasValue ? OuterEnumTestValueConverter.ToJsonValue(outerEnumTest.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/PetStatus.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/PetStatus.cs
index 9e19b612bf9..52de1419c80 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/PetStatus.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/PetStatus.cs
@@ -145,7 +145,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, PetStatus petStatus, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(petStatus.ToString());
+            writer.WriteStringValue(PetStatusValueConverter.ToJsonValue(petStatus).ToString());
         }
     }
 
@@ -176,14 +176,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the PetStatus to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="petStatus"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, PetStatus? petStatus, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(petStatus?.ToString() ?? "null");
+            writer.WriteStringValue(petStatus.HasValue ? PetStatusValueConverter.ToJsonValue(petStatus.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumInteger.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumInteger.cs
index 04988ef3ee9..fcdc5507481 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumInteger.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumInteger.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNotnullableEnumInteger requiredClassRequiredNotnullableEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNotnullableEnumInteger.ToString());
+            writer.WriteStringValue(RequiredClassRequiredNotnullableEnumIntegerValueConverter.ToJsonValue(requiredClassRequiredNotnullableEnumInteger).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the RequiredClassRequiredNotnullableEnumInteger to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="requiredClassRequiredNotnullableEnumInteger"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNotnullableEnumInteger? requiredClassRequiredNotnullableEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNotnullableEnumInteger?.ToString() ?? "null");
+            writer.WriteStringValue(requiredClassRequiredNotnullableEnumInteger.HasValue ? RequiredClassRequiredNotnullableEnumIntegerValueConverter.ToJsonValue(requiredClassRequiredNotnullableEnumInteger.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumIntegerOnly.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumIntegerOnly.cs
index 775aba4f6af..1d33399c633 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumIntegerOnly.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumIntegerOnly.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNotnullableEnumIntegerOnly requiredClassRequiredNotnullableEnumIntegerOnly, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNotnullableEnumIntegerOnly.ToString());
+            writer.WriteStringValue(RequiredClassRequiredNotnullableEnumIntegerOnlyValueConverter.ToJsonValue(requiredClassRequiredNotnullableEnumIntegerOnly).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the RequiredClassRequiredNotnullableEnumIntegerOnly to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="requiredClassRequiredNotnullableEnumIntegerOnly"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNotnullableEnumIntegerOnly? requiredClassRequiredNotnullableEnumIntegerOnly, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNotnullableEnumIntegerOnly?.ToString() ?? "null");
+            writer.WriteStringValue(requiredClassRequiredNotnullableEnumIntegerOnly.HasValue ? RequiredClassRequiredNotnullableEnumIntegerOnlyValueConverter.ToJsonValue(requiredClassRequiredNotnullableEnumIntegerOnly.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumString.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumString.cs
index 5b4f29294ac..1e251fee921 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumString.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNotnullableEnumString.cs
@@ -214,7 +214,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNotnullableEnumString requiredClassRequiredNotnullableEnumString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNotnullableEnumString.ToString());
+            writer.WriteStringValue(RequiredClassRequiredNotnullableEnumStringValueConverter.ToJsonValue(requiredClassRequiredNotnullableEnumString).ToString());
         }
     }
 
@@ -245,14 +245,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the RequiredClassRequiredNotnullableEnumString to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="requiredClassRequiredNotnullableEnumString"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNotnullableEnumString? requiredClassRequiredNotnullableEnumString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNotnullableEnumString?.ToString() ?? "null");
+            writer.WriteStringValue(requiredClassRequiredNotnullableEnumString.HasValue ? RequiredClassRequiredNotnullableEnumStringValueConverter.ToJsonValue(requiredClassRequiredNotnullableEnumString.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumInteger.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumInteger.cs
index 365504a241b..97db2037f95 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumInteger.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumInteger.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNullableEnumInteger requiredClassRequiredNullableEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNullableEnumInteger.ToString());
+            writer.WriteStringValue(RequiredClassRequiredNullableEnumIntegerValueConverter.ToJsonValue(requiredClassRequiredNullableEnumInteger).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the RequiredClassRequiredNullableEnumInteger to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="requiredClassRequiredNullableEnumInteger"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNullableEnumInteger? requiredClassRequiredNullableEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNullableEnumInteger?.ToString() ?? "null");
+            writer.WriteStringValue(requiredClassRequiredNullableEnumInteger.HasValue ? RequiredClassRequiredNullableEnumIntegerValueConverter.ToJsonValue(requiredClassRequiredNullableEnumInteger.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumIntegerOnly.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumIntegerOnly.cs
index 4c5f2c56ba5..2f53261cd6f 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumIntegerOnly.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumIntegerOnly.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNullableEnumIntegerOnly requiredClassRequiredNullableEnumIntegerOnly, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNullableEnumIntegerOnly.ToString());
+            writer.WriteStringValue(RequiredClassRequiredNullableEnumIntegerOnlyValueConverter.ToJsonValue(requiredClassRequiredNullableEnumIntegerOnly).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the RequiredClassRequiredNullableEnumIntegerOnly to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="requiredClassRequiredNullableEnumIntegerOnly"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNullableEnumIntegerOnly? requiredClassRequiredNullableEnumIntegerOnly, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNullableEnumIntegerOnly?.ToString() ?? "null");
+            writer.WriteStringValue(requiredClassRequiredNullableEnumIntegerOnly.HasValue ? RequiredClassRequiredNullableEnumIntegerOnlyValueConverter.ToJsonValue(requiredClassRequiredNullableEnumIntegerOnly.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumString.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumString.cs
index 36bcb148131..7efe892e924 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumString.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/RequiredClassRequiredNullableEnumString.cs
@@ -214,7 +214,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNullableEnumString requiredClassRequiredNullableEnumString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNullableEnumString.ToString());
+            writer.WriteStringValue(RequiredClassRequiredNullableEnumStringValueConverter.ToJsonValue(requiredClassRequiredNullableEnumString).ToString());
         }
     }
 
@@ -245,14 +245,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the RequiredClassRequiredNullableEnumString to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="requiredClassRequiredNullableEnumString"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, RequiredClassRequiredNullableEnumString? requiredClassRequiredNullableEnumString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(requiredClassRequiredNullableEnumString?.ToString() ?? "null");
+            writer.WriteStringValue(requiredClassRequiredNullableEnumString.HasValue ? RequiredClassRequiredNullableEnumStringValueConverter.ToJsonValue(requiredClassRequiredNullableEnumString.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestDescendantsObjectType.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestDescendantsObjectType.cs
index 32fdf9b1c3b..0c0c757cc59 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestDescendantsObjectType.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestDescendantsObjectType.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestDescendantsObjectType testDescendantsObjectType, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testDescendantsObjectType.ToString());
+            writer.WriteStringValue(TestDescendantsObjectTypeValueConverter.ToJsonValue(testDescendantsObjectType).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestDescendantsObjectType to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testDescendantsObjectType"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestDescendantsObjectType? testDescendantsObjectType, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testDescendantsObjectType?.ToString() ?? "null");
+            writer.WriteStringValue(testDescendantsObjectType.HasValue ? TestDescendantsObjectTypeValueConverter.ToJsonValue(testDescendantsObjectType.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumHeaderStringParameter.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumHeaderStringParameter.cs
index ccb446b0250..4fe8d2deb70 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumHeaderStringParameter.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumHeaderStringParameter.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersEnumHeaderStringParameter testEnumParametersEnumHeaderStringParameter, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersEnumHeaderStringParameter.ToString());
+            writer.WriteStringValue(TestEnumParametersEnumHeaderStringParameterValueConverter.ToJsonValue(testEnumParametersEnumHeaderStringParameter).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestEnumParametersEnumHeaderStringParameter to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testEnumParametersEnumHeaderStringParameter"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersEnumHeaderStringParameter? testEnumParametersEnumHeaderStringParameter, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersEnumHeaderStringParameter?.ToString() ?? "null");
+            writer.WriteStringValue(testEnumParametersEnumHeaderStringParameter.HasValue ? TestEnumParametersEnumHeaderStringParameterValueConverter.ToJsonValue(testEnumParametersEnumHeaderStringParameter.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryDoubleParameter.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryDoubleParameter.cs
index ec14b39944d..d4d97e76043 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryDoubleParameter.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryDoubleParameter.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersEnumQueryDoubleParameter testEnumParametersEnumQueryDoubleParameter, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersEnumQueryDoubleParameter.ToString());
+            writer.WriteStringValue(TestEnumParametersEnumQueryDoubleParameterValueConverter.ToJsonValue(testEnumParametersEnumQueryDoubleParameter).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestEnumParametersEnumQueryDoubleParameter to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testEnumParametersEnumQueryDoubleParameter"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersEnumQueryDoubleParameter? testEnumParametersEnumQueryDoubleParameter, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersEnumQueryDoubleParameter?.ToString() ?? "null");
+            writer.WriteStringValue(testEnumParametersEnumQueryDoubleParameter.HasValue ? TestEnumParametersEnumQueryDoubleParameterValueConverter.ToJsonValue(testEnumParametersEnumQueryDoubleParameter.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryIntegerParameter.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryIntegerParameter.cs
index 33ff2ce2cc2..85149c3f5eb 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryIntegerParameter.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersEnumQueryIntegerParameter.cs
@@ -124,7 +124,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersEnumQueryIntegerParameter testEnumParametersEnumQueryIntegerParameter, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersEnumQueryIntegerParameter.ToString());
+            writer.WriteStringValue(TestEnumParametersEnumQueryIntegerParameterValueConverter.ToJsonValue(testEnumParametersEnumQueryIntegerParameter).ToString());
         }
     }
 
@@ -155,14 +155,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestEnumParametersEnumQueryIntegerParameter to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testEnumParametersEnumQueryIntegerParameter"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersEnumQueryIntegerParameter? testEnumParametersEnumQueryIntegerParameter, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersEnumQueryIntegerParameter?.ToString() ?? "null");
+            writer.WriteStringValue(testEnumParametersEnumQueryIntegerParameter.HasValue ? TestEnumParametersEnumQueryIntegerParameterValueConverter.ToJsonValue(testEnumParametersEnumQueryIntegerParameter.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormString.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormString.cs
index d86b48d4a9b..2e81a11c33b 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormString.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormString.cs
@@ -145,7 +145,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersRequestEnumFormString testEnumParametersRequestEnumFormString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersRequestEnumFormString.ToString());
+            writer.WriteStringValue(TestEnumParametersRequestEnumFormStringValueConverter.ToJsonValue(testEnumParametersRequestEnumFormString).ToString());
         }
     }
 
@@ -176,14 +176,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestEnumParametersRequestEnumFormString to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testEnumParametersRequestEnumFormString"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersRequestEnumFormString? testEnumParametersRequestEnumFormString, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersRequestEnumFormString?.ToString() ?? "null");
+            writer.WriteStringValue(testEnumParametersRequestEnumFormString.HasValue ? TestEnumParametersRequestEnumFormStringValueConverter.ToJsonValue(testEnumParametersRequestEnumFormString.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormStringArrayInner.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormStringArrayInner.cs
index 4f1c9c53c60..5c00030c30a 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormStringArrayInner.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestEnumParametersRequestEnumFormStringArrayInner.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersRequestEnumFormStringArrayInner testEnumParametersRequestEnumFormStringArrayInner, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersRequestEnumFormStringArrayInner.ToString());
+            writer.WriteStringValue(TestEnumParametersRequestEnumFormStringArrayInnerValueConverter.ToJsonValue(testEnumParametersRequestEnumFormStringArrayInner).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestEnumParametersRequestEnumFormStringArrayInner to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testEnumParametersRequestEnumFormStringArrayInner"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestEnumParametersRequestEnumFormStringArrayInner? testEnumParametersRequestEnumFormStringArrayInner, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testEnumParametersRequestEnumFormStringArrayInner?.ToString() ?? "null");
+            writer.WriteStringValue(testEnumParametersRequestEnumFormStringArrayInner.HasValue ? TestEnumParametersRequestEnumFormStringArrayInnerValueConverter.ToJsonValue(testEnumParametersRequestEnumFormStringArrayInner.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestResultCode.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestResultCode.cs
index 0fc06c04a67..280c9b82cfa 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestResultCode.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/TestResultCode.cs
@@ -131,7 +131,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestResultCode testResultCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testResultCode.ToString());
+            writer.WriteStringValue(TestResultCodeValueConverter.ToJsonValue(testResultCode).ToString());
         }
     }
 
@@ -162,14 +162,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestResultCode to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testResultCode"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestResultCode? testResultCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testResultCode?.ToString() ?? "null");
+            writer.WriteStringValue(testResultCode.HasValue ? TestResultCodeValueConverter.ToJsonValue(testResultCode.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/ZebraType.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/ZebraType.cs
index 4a54f2a265a..5eb8d6bac71 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/ZebraType.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/ZebraType.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZebraType zebraType, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zebraType.ToString());
+            writer.WriteStringValue(ZebraTypeValueConverter.ToJsonValue(zebraType).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the ZebraType to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="zebraType"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZebraType? zebraType, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zebraType?.ToString() ?? "null");
+            writer.WriteStringValue(zebraType.HasValue ? ZebraTypeValueConverter.ToJsonValue(zebraType.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
index 34a044fb8b1..b82155f7800 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnum zeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnum.ToString());
+            writer.WriteStringValue(ZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnum).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the ZeroBasedEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="zeroBasedEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnum? zeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnum?.ToString() ?? "null");
+            writer.WriteStringValue(zeroBasedEnum.HasValue ? ZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnum.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnumClassZeroBasedEnum.cs b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnumClassZeroBasedEnum.cs
index 2b062a550ab..cb6f10e40b3 100644
--- a/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnumClassZeroBasedEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net9/FormModels/src/Org.OpenAPITools/Model/ZeroBasedEnumClassZeroBasedEnum.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnumClassZeroBasedEnum zeroBasedEnumClassZeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnumClassZeroBasedEnum.ToString());
+            writer.WriteStringValue(ZeroBasedEnumClassZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnumClassZeroBasedEnum).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the ZeroBasedEnumClassZeroBasedEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="zeroBasedEnumClassZeroBasedEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnumClassZeroBasedEnum? zeroBasedEnumClassZeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnumClassZeroBasedEnum?.ToString() ?? "null");
+            writer.WriteStringValue(zeroBasedEnumClassZeroBasedEnum.HasValue ? ZeroBasedEnumClassZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnumClassZeroBasedEnum.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/EnumClass.cs b/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/EnumClass.cs
index 03b2780c484..592f6a59c31 100644
--- a/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/EnumClass.cs
+++ b/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/EnumClass.cs
@@ -146,7 +146,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass.ToString());
+            writer.WriteStringValue(EnumClassValueConverter.ToJsonValue(enumClass).ToString());
         }
     }
 
@@ -177,14 +177,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumClass to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumClass"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass? enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass?.ToString() ?? "null");
+            writer.WriteStringValue(enumClass.HasValue ? EnumClassValueConverter.ToJsonValue(enumClass.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnum.cs b/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnum.cs
index 96af6f3670d..0476c873cd8 100644
--- a/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnum.cs
@@ -146,7 +146,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnum outerEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnum.ToString());
+            writer.WriteStringValue(OuterEnumValueConverter.ToJsonValue(outerEnum).ToString());
         }
     }
 
@@ -177,14 +177,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnum? outerEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnum?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnum.HasValue ? OuterEnumValueConverter.ToJsonValue(outerEnum.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs b/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
index a50d5c056ec..68faa3cd5de 100644
--- a/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
+++ b/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
@@ -146,7 +146,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumDefaultValue outerEnumDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumDefaultValue.ToString());
+            writer.WriteStringValue(OuterEnumDefaultValueValueConverter.ToJsonValue(outerEnumDefaultValue).ToString());
         }
     }
 
@@ -177,14 +177,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumDefaultValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumDefaultValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumDefaultValue? outerEnumDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumDefaultValue?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumDefaultValue.HasValue ? OuterEnumDefaultValueValueConverter.ToJsonValue(outerEnumDefaultValue.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumInteger.cs b/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
index 41ecebcf8f5..6ba997e06eb 100644
--- a/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
+++ b/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
@@ -137,7 +137,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumInteger outerEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumInteger.ToString());
+            writer.WriteStringValue(OuterEnumIntegerValueConverter.ToJsonValue(outerEnumInteger).ToString());
         }
     }
 
@@ -168,14 +168,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumInteger to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumInteger"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumInteger? outerEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumInteger?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumInteger.HasValue ? OuterEnumIntegerValueConverter.ToJsonValue(outerEnumInteger.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs b/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
index 902dbb06639..d8d27e54ee3 100644
--- a/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
+++ b/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
@@ -137,7 +137,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumIntegerDefaultValue outerEnumIntegerDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumIntegerDefaultValue.ToString());
+            writer.WriteStringValue(OuterEnumIntegerDefaultValueValueConverter.ToJsonValue(outerEnumIntegerDefaultValue).ToString());
         }
     }
 
@@ -168,14 +168,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumIntegerDefaultValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumIntegerDefaultValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumIntegerDefaultValue? outerEnumIntegerDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumIntegerDefaultValue?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumIntegerDefaultValue.HasValue ? OuterEnumIntegerDefaultValueValueConverter.ToJsonValue(outerEnumIntegerDefaultValue.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumTest.cs b/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumTest.cs
index 03a8ccdecac..5a1f2a6e439 100644
--- a/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumTest.cs
+++ b/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/OuterEnumTest.cs
@@ -216,7 +216,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumTest outerEnumTest, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumTest.ToString());
+            writer.WriteStringValue(OuterEnumTestValueConverter.ToJsonValue(outerEnumTest).ToString());
         }
     }
 
@@ -247,14 +247,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumTest to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumTest"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumTest? outerEnumTest, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumTest?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumTest.HasValue ? OuterEnumTestValueConverter.ToJsonValue(outerEnumTest.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/TestResultCode.cs b/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/TestResultCode.cs
index 2523ba0414a..f53e8d34214 100644
--- a/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/TestResultCode.cs
+++ b/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/TestResultCode.cs
@@ -133,7 +133,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestResultCode testResultCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testResultCode.ToString());
+            writer.WriteStringValue(TestResultCodeValueConverter.ToJsonValue(testResultCode).ToString());
         }
     }
 
@@ -164,14 +164,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestResultCode to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testResultCode"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestResultCode? testResultCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testResultCode?.ToString() ?? "null");
+            writer.WriteStringValue(testResultCode.HasValue ? TestResultCodeValueConverter.ToJsonValue(testResultCode.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs b/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
index 1db14d35a9e..5434f2b84ea 100644
--- a/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net9/NullReferenceTypes/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
@@ -132,7 +132,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnum zeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnum.ToString());
+            writer.WriteStringValue(ZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnum).ToString());
         }
     }
 
@@ -163,14 +163,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the ZeroBasedEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="zeroBasedEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnum? zeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnum?.ToString() ?? "null");
+            writer.WriteStringValue(zeroBasedEnum.HasValue ? ZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnum.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/EnumClass.cs b/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/EnumClass.cs
index b1aff0adf0d..cefbf28588f 100644
--- a/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/EnumClass.cs
+++ b/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/EnumClass.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass.ToString());
+            writer.WriteStringValue(EnumClassValueConverter.ToJsonValue(enumClass).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumClass to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumClass"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass? enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass?.ToString() ?? "null");
+            writer.WriteStringValue(enumClass.HasValue ? EnumClassValueConverter.ToJsonValue(enumClass.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/OuterEnum.cs b/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/OuterEnum.cs
index 47bb6793c6a..e72ea52b087 100644
--- a/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/OuterEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/OuterEnum.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnum outerEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnum.ToString());
+            writer.WriteStringValue(OuterEnumValueConverter.ToJsonValue(outerEnum).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnum? outerEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnum?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnum.HasValue ? OuterEnumValueConverter.ToJsonValue(outerEnum.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs b/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
index 136fb4c54c4..e2c52f962f3 100644
--- a/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
+++ b/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumDefaultValue outerEnumDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumDefaultValue.ToString());
+            writer.WriteStringValue(OuterEnumDefaultValueValueConverter.ToJsonValue(outerEnumDefaultValue).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumDefaultValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumDefaultValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumDefaultValue? outerEnumDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumDefaultValue?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumDefaultValue.HasValue ? OuterEnumDefaultValueValueConverter.ToJsonValue(outerEnumDefaultValue.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/OuterEnumInteger.cs b/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
index 2ed4f18a657..e3812cb3198 100644
--- a/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
+++ b/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
@@ -135,7 +135,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumInteger outerEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumInteger.ToString());
+            writer.WriteStringValue(OuterEnumIntegerValueConverter.ToJsonValue(outerEnumInteger).ToString());
         }
     }
 
@@ -166,14 +166,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumInteger to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumInteger"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumInteger? outerEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumInteger?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumInteger.HasValue ? OuterEnumIntegerValueConverter.ToJsonValue(outerEnumInteger.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs b/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
index c6a470cc64d..296151997b0 100644
--- a/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
+++ b/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
@@ -135,7 +135,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumIntegerDefaultValue outerEnumIntegerDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumIntegerDefaultValue.ToString());
+            writer.WriteStringValue(OuterEnumIntegerDefaultValueValueConverter.ToJsonValue(outerEnumIntegerDefaultValue).ToString());
         }
     }
 
@@ -166,14 +166,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumIntegerDefaultValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumIntegerDefaultValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumIntegerDefaultValue? outerEnumIntegerDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumIntegerDefaultValue?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumIntegerDefaultValue.HasValue ? OuterEnumIntegerDefaultValueValueConverter.ToJsonValue(outerEnumIntegerDefaultValue.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/OuterEnumTest.cs b/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/OuterEnumTest.cs
index a2e789f2ede..b4c4e25a9bb 100644
--- a/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/OuterEnumTest.cs
+++ b/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/OuterEnumTest.cs
@@ -214,7 +214,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumTest outerEnumTest, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumTest.ToString());
+            writer.WriteStringValue(OuterEnumTestValueConverter.ToJsonValue(outerEnumTest).ToString());
         }
     }
 
@@ -245,14 +245,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumTest to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumTest"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumTest? outerEnumTest, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumTest?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumTest.HasValue ? OuterEnumTestValueConverter.ToJsonValue(outerEnumTest.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/TestResultCode.cs b/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/TestResultCode.cs
index 0fc06c04a67..280c9b82cfa 100644
--- a/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/TestResultCode.cs
+++ b/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/TestResultCode.cs
@@ -131,7 +131,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestResultCode testResultCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testResultCode.ToString());
+            writer.WriteStringValue(TestResultCodeValueConverter.ToJsonValue(testResultCode).ToString());
         }
     }
 
@@ -162,14 +162,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestResultCode to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testResultCode"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestResultCode? testResultCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testResultCode?.ToString() ?? "null");
+            writer.WriteStringValue(testResultCode.HasValue ? TestResultCodeValueConverter.ToJsonValue(testResultCode.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs b/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
index 34a044fb8b1..b82155f7800 100644
--- a/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net9/Petstore/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnum zeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnum.ToString());
+            writer.WriteStringValue(ZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnum).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the ZeroBasedEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="zeroBasedEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnum? zeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnum?.ToString() ?? "null");
+            writer.WriteStringValue(zeroBasedEnum.HasValue ? ZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnum.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/EnumClass.cs b/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/EnumClass.cs
index 520dc1cfbde..6192d15c9f5 100644
--- a/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/EnumClass.cs
+++ b/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/EnumClass.cs
@@ -147,7 +147,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass.ToString());
+            writer.WriteStringValue(EnumClassValueConverter.ToJsonValue(enumClass).ToString());
         }
     }
 
@@ -178,14 +178,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumClass to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumClass"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass? enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass?.ToString() ?? "null");
+            writer.WriteStringValue(enumClass.HasValue ? EnumClassValueConverter.ToJsonValue(enumClass.Value).ToString() : "null");
         }
     }
 
diff --git a/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnum.cs b/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnum.cs
index 803ca5e1771..c2b58fa0eba 100644
--- a/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnum.cs
@@ -147,7 +147,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnum outerEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnum.ToString());
+            writer.WriteStringValue(OuterEnumValueConverter.ToJsonValue(outerEnum).ToString());
         }
     }
 
@@ -178,14 +178,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnum? outerEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnum?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnum.HasValue ? OuterEnumValueConverter.ToJsonValue(outerEnum.Value).ToString() : "null");
         }
     }
 
diff --git a/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs b/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
index 1d30a9abb74..fa6acccc08e 100644
--- a/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
+++ b/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
@@ -147,7 +147,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumDefaultValue outerEnumDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumDefaultValue.ToString());
+            writer.WriteStringValue(OuterEnumDefaultValueValueConverter.ToJsonValue(outerEnumDefaultValue).ToString());
         }
     }
 
@@ -178,14 +178,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumDefaultValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumDefaultValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumDefaultValue? outerEnumDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumDefaultValue?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumDefaultValue.HasValue ? OuterEnumDefaultValueValueConverter.ToJsonValue(outerEnumDefaultValue.Value).ToString() : "null");
         }
     }
 
diff --git a/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumInteger.cs b/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
index 0d9bcfd0835..362553f662a 100644
--- a/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
+++ b/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
@@ -138,7 +138,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumInteger outerEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumInteger.ToString());
+            writer.WriteStringValue(OuterEnumIntegerValueConverter.ToJsonValue(outerEnumInteger).ToString());
         }
     }
 
@@ -169,14 +169,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumInteger to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumInteger"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumInteger? outerEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumInteger?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumInteger.HasValue ? OuterEnumIntegerValueConverter.ToJsonValue(outerEnumInteger.Value).ToString() : "null");
         }
     }
 
diff --git a/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs b/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
index b0d7b8ea075..fba1de8e6f3 100644
--- a/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
+++ b/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
@@ -138,7 +138,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumIntegerDefaultValue outerEnumIntegerDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumIntegerDefaultValue.ToString());
+            writer.WriteStringValue(OuterEnumIntegerDefaultValueValueConverter.ToJsonValue(outerEnumIntegerDefaultValue).ToString());
         }
     }
 
@@ -169,14 +169,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumIntegerDefaultValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumIntegerDefaultValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumIntegerDefaultValue? outerEnumIntegerDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumIntegerDefaultValue?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumIntegerDefaultValue.HasValue ? OuterEnumIntegerDefaultValueValueConverter.ToJsonValue(outerEnumIntegerDefaultValue.Value).ToString() : "null");
         }
     }
 
diff --git a/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumTest.cs b/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumTest.cs
index 56a81b57e54..b8716ad2b25 100644
--- a/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumTest.cs
+++ b/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/OuterEnumTest.cs
@@ -217,7 +217,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumTest outerEnumTest, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumTest.ToString());
+            writer.WriteStringValue(OuterEnumTestValueConverter.ToJsonValue(outerEnumTest).ToString());
         }
     }
 
@@ -248,14 +248,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumTest to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumTest"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumTest? outerEnumTest, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumTest?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumTest.HasValue ? OuterEnumTestValueConverter.ToJsonValue(outerEnumTest.Value).ToString() : "null");
         }
     }
 
diff --git a/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/TestResultCode.cs b/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/TestResultCode.cs
index 4d4a979a814..029a66af518 100644
--- a/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/TestResultCode.cs
+++ b/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/TestResultCode.cs
@@ -134,7 +134,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestResultCode testResultCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testResultCode.ToString());
+            writer.WriteStringValue(TestResultCodeValueConverter.ToJsonValue(testResultCode).ToString());
         }
     }
 
@@ -165,14 +165,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestResultCode to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testResultCode"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestResultCode? testResultCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testResultCode?.ToString() ?? "null");
+            writer.WriteStringValue(testResultCode.HasValue ? TestResultCodeValueConverter.ToJsonValue(testResultCode.Value).ToString() : "null");
         }
     }
 
diff --git a/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs b/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
index 15c22d0fc3b..c553e7d9ef5 100644
--- a/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
+++ b/samples/client/petstore/csharp/generichost/net9/SourceGeneration/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
@@ -133,7 +133,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnum zeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnum.ToString());
+            writer.WriteStringValue(ZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnum).ToString());
         }
     }
 
@@ -164,14 +164,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the ZeroBasedEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="zeroBasedEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnum? zeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnum?.ToString() ?? "null");
+            writer.WriteStringValue(zeroBasedEnum.HasValue ? ZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnum.Value).ToString() : "null");
         }
     }
 
diff --git a/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/EnumClass.cs b/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/EnumClass.cs
index b1aff0adf0d..cefbf28588f 100644
--- a/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/EnumClass.cs
+++ b/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/EnumClass.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass.ToString());
+            writer.WriteStringValue(EnumClassValueConverter.ToJsonValue(enumClass).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the EnumClass to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="enumClass"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, EnumClass? enumClass, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(enumClass?.ToString() ?? "null");
+            writer.WriteStringValue(enumClass.HasValue ? EnumClassValueConverter.ToJsonValue(enumClass.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/OuterEnum.cs b/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/OuterEnum.cs
index 47bb6793c6a..e72ea52b087 100644
--- a/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/OuterEnum.cs
+++ b/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/OuterEnum.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnum outerEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnum.ToString());
+            writer.WriteStringValue(OuterEnumValueConverter.ToJsonValue(outerEnum).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnum? outerEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnum?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnum.HasValue ? OuterEnumValueConverter.ToJsonValue(outerEnum.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs b/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
index 136fb4c54c4..e2c52f962f3 100644
--- a/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
+++ b/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/OuterEnumDefaultValue.cs
@@ -144,7 +144,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumDefaultValue outerEnumDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumDefaultValue.ToString());
+            writer.WriteStringValue(OuterEnumDefaultValueValueConverter.ToJsonValue(outerEnumDefaultValue).ToString());
         }
     }
 
@@ -175,14 +175,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumDefaultValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumDefaultValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumDefaultValue? outerEnumDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumDefaultValue?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumDefaultValue.HasValue ? OuterEnumDefaultValueValueConverter.ToJsonValue(outerEnumDefaultValue.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/OuterEnumInteger.cs b/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
index 2ed4f18a657..e3812cb3198 100644
--- a/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
+++ b/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/OuterEnumInteger.cs
@@ -135,7 +135,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumInteger outerEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumInteger.ToString());
+            writer.WriteStringValue(OuterEnumIntegerValueConverter.ToJsonValue(outerEnumInteger).ToString());
         }
     }
 
@@ -166,14 +166,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumInteger to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumInteger"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumInteger? outerEnumInteger, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumInteger?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumInteger.HasValue ? OuterEnumIntegerValueConverter.ToJsonValue(outerEnumInteger.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs b/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
index c6a470cc64d..296151997b0 100644
--- a/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
+++ b/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/OuterEnumIntegerDefaultValue.cs
@@ -135,7 +135,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumIntegerDefaultValue outerEnumIntegerDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumIntegerDefaultValue.ToString());
+            writer.WriteStringValue(OuterEnumIntegerDefaultValueValueConverter.ToJsonValue(outerEnumIntegerDefaultValue).ToString());
         }
     }
 
@@ -166,14 +166,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumIntegerDefaultValue to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumIntegerDefaultValue"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumIntegerDefaultValue? outerEnumIntegerDefaultValue, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumIntegerDefaultValue?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumIntegerDefaultValue.HasValue ? OuterEnumIntegerDefaultValueValueConverter.ToJsonValue(outerEnumIntegerDefaultValue.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/OuterEnumTest.cs b/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/OuterEnumTest.cs
index a2e789f2ede..b4c4e25a9bb 100644
--- a/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/OuterEnumTest.cs
+++ b/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/OuterEnumTest.cs
@@ -214,7 +214,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumTest outerEnumTest, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumTest.ToString());
+            writer.WriteStringValue(OuterEnumTestValueConverter.ToJsonValue(outerEnumTest).ToString());
         }
     }
 
@@ -245,14 +245,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the OuterEnumTest to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="outerEnumTest"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, OuterEnumTest? outerEnumTest, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(outerEnumTest?.ToString() ?? "null");
+            writer.WriteStringValue(outerEnumTest.HasValue ? OuterEnumTestValueConverter.ToJsonValue(outerEnumTest.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/TestResultCode.cs b/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/TestResultCode.cs
index 0fc06c04a67..280c9b82cfa 100644
--- a/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/TestResultCode.cs
+++ b/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/TestResultCode.cs
@@ -131,7 +131,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestResultCode testResultCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testResultCode.ToString());
+            writer.WriteStringValue(TestResultCodeValueConverter.ToJsonValue(testResultCode).ToString());
         }
     }
 
@@ -162,14 +162,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the TestResultCode to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="testResultCode"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, TestResultCode? testResultCode, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(testResultCode?.ToString() ?? "null");
+            writer.WriteStringValue(testResultCode.HasValue ? TestResultCodeValueConverter.ToJsonValue(testResultCode.Value).ToString() : "null");
         }
     }
 }
diff --git a/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs b/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
index 34a044fb8b1..b82155f7800 100644
--- a/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
+++ b/samples/client/petstore/csharp/generichost/standard2.0/Petstore/src/Org.OpenAPITools/Model/ZeroBasedEnum.cs
@@ -130,7 +130,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnum zeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnum.ToString());
+            writer.WriteStringValue(ZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnum).ToString());
         }
     }
 
@@ -161,14 +161,14 @@ namespace Org.OpenAPITools.Model
         }
 
         /// <summary>
-        /// Writes the DateTime to the json writer
+        /// Writes the ZeroBasedEnum to the json writer
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="zeroBasedEnum"></param>
         /// <param name="options"></param>
         public override void Write(Utf8JsonWriter writer, ZeroBasedEnum? zeroBasedEnum, JsonSerializerOptions options)
         {
-            writer.WriteStringValue(zeroBasedEnum?.ToString() ?? "null");
+            writer.WriteStringValue(zeroBasedEnum.HasValue ? ZeroBasedEnumValueConverter.ToJsonValue(zeroBasedEnum.Value).ToString() : "null");
         }
     }
 }