diff --git a/lib/codegen/fromcto/csharp/csharpvisitor.js b/lib/codegen/fromcto/csharp/csharpvisitor.js
index 10f40d72..ce5e351d 100644
--- a/lib/codegen/fromcto/csharp/csharpvisitor.js
+++ b/lib/codegen/fromcto/csharp/csharpvisitor.js
@@ -1,3 +1,4 @@
+/* eslint-disable no-unreachable */
 /*
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -312,11 +313,40 @@ class CSharpVisitor {
      * @private
      */
     writeField(field, parameters, externalFieldType, isOptional = false) {
-
         // write Map field
-        if (Object.keys(field).length > 0 && ModelUtil.isMap?.(field)) {
-            const decl = field.getModelFile().getType(field.getType());
-            parameters.fileWriter.writeLine(1, `public Dictionary<string, ${this.toCSharpType(decl.getValue().getType())}> ${field.getName()} { get; set; }`);
+        if (ModelUtil.isMap?.(field)) {
+            const mapDeclaration = field.getModelFile().getType(field.getType());
+            const mapKeyType     = mapDeclaration.getKey().getType();
+            const mapValueType   = mapDeclaration.getValue().getType();
+
+            let keyType;
+            let valueType;
+
+            // Map Key
+            if (ModelUtil.isPrimitiveType(mapKeyType)) {
+                keyType = this.toCSharpType(mapKeyType);
+            }
+            else if (ModelUtil.isScalar(mapDeclaration.getKey())) {
+                const scalarDeclaration = mapDeclaration.getModelFile().getType(mapDeclaration.getKey().getType());
+                const keyFQN = ModelUtil.removeNamespaceVersionFromFullyQualifiedName(scalarDeclaration.getFullyQualifiedName());
+                const scalarType = keyFQN === 'concerto.scalar.UUID' ? keyFQN : scalarDeclaration.getType();
+                keyType = this.toCSharpType(scalarType);
+            }
+
+            // Map Value
+            if (ModelUtil.isPrimitiveType(mapValueType)) {
+                valueType = this.toCSharpType(mapValueType);
+            }
+            else if (ModelUtil.isScalar(mapDeclaration.getValue())) {
+                const scalarDeclaration = mapDeclaration.getModelFile().getType(mapDeclaration.getValue().getType());
+                const keyFQN = ModelUtil.removeNamespaceVersionFromFullyQualifiedName(scalarDeclaration.getFullyQualifiedName());
+                const scalarType = keyFQN === 'concerto.scalar.UUID' ? keyFQN : scalarDeclaration.getType();
+                valueType = this.toCSharpType(scalarType);
+            } else {
+                valueType = mapValueType;
+            }
+
+            parameters.fileWriter.writeLine(1, `public Dictionary<${keyType}, ${valueType}> ${field.getName()} { get; set; }`);
             return null;
         }
 
diff --git a/test/codegen/__snapshots__/codegen.js.snap b/test/codegen/__snapshots__/codegen.js.snap
index 7bf8e183..4ead9dc6 100644
--- a/test/codegen/__snapshots__/codegen.js.snap
+++ b/test/codegen/__snapshots__/codegen.js.snap
@@ -382,7 +382,7 @@ public class Company : Concept {
    public Dictionary<string, Employee> employeeDirectory { get; set; }
    public Dictionary<string, TShirtSizeType> employeeTShirtSizes { get; set; }
    public Dictionary<string, Concept> employeeProfiles { get; set; }
-   public Dictionary<string, SSN> employeeSocialSecurityNumbers { get; set; }
+   public Dictionary<string, string> employeeSocialSecurityNumbers { get; set; }
 }
 [System.Text.Json.Serialization.JsonConverter(typeof(System.Text.Json.Serialization.JsonStringEnumConverter))]
 public enum Department {
@@ -428,7 +428,7 @@ public abstract class Person : Participant {
    public string ssn { get; set; }
    public float height { get; set; }
    public System.DateTime dob { get; set; }
-   public Dictionary<string, KinTelephone> nextOfKin { get; set; }
+   public Dictionary<string, string> nextOfKin { get; set; }
 }
 [AccordProject.Concerto.Type(Namespace = "org.acme.hr", Version = null, Name = "Employee")]
 [System.Text.Json.Serialization.JsonConverter(typeof(AccordProject.Concerto.ConcertoConverterFactorySystem))]
@@ -5932,7 +5932,7 @@ public class Company : Concept {
    public Dictionary<string, Employee> employeeDirectory { get; set; }
    public Dictionary<string, TShirtSizeType> employeeTShirtSizes { get; set; }
    public Dictionary<string, Concept> employeeProfiles { get; set; }
-   public Dictionary<string, SSN> employeeSocialSecurityNumbers { get; set; }
+   public Dictionary<string, string> employeeSocialSecurityNumbers { get; set; }
 }
 [System.Text.Json.Serialization.JsonConverter(typeof(System.Text.Json.Serialization.JsonStringEnumConverter))]
 public enum Department {
@@ -5978,7 +5978,7 @@ public abstract class Person : Participant {
    public string ssn { get; set; }
    public float height { get; set; }
    public System.DateTime dob { get; set; }
-   public Dictionary<string, KinTelephone> nextOfKin { get; set; }
+   public Dictionary<string, string> nextOfKin { get; set; }
 }
 [AccordProject.Concerto.Type(Namespace = "org.acme.hr", Version = "1.0.0", Name = "Employee")]
 [System.Text.Json.Serialization.JsonConverter(typeof(AccordProject.Concerto.ConcertoConverterFactorySystem))]
diff --git a/test/codegen/fromcto/csharp/csharpvisitor.js b/test/codegen/fromcto/csharp/csharpvisitor.js
index 28c5af63..1e9640e6 100644
--- a/test/codegen/fromcto/csharp/csharpvisitor.js
+++ b/test/codegen/fromcto/csharp/csharpvisitor.js
@@ -1445,7 +1445,7 @@ public class SampleModel : Concept {
             };
             sandbox.restore();
             sandbox.stub(ModelUtil, 'isMap').callsFake(() => {
-                return true;
+                return false;
             });
 
         });
@@ -1509,6 +1509,11 @@ public class SampleModel : Concept {
             mockField.dummy = 'Dummy Value';
             mockField.getModelFile.returns({ getType: getType });
 
+            sandbox.restore();
+            sandbox.stub(ModelUtil, 'isMap').callsFake(() => {
+                return true;
+            });
+
             const mockMapDeclaration    = sinon.createStubInstance(MapDeclaration);
             const getKeyType            = sinon.stub();
             const getValueType          = sinon.stub();
@@ -1533,11 +1538,22 @@ public class SampleModel : Concept {
             mockField.dummy = 'Dummy Value';
             mockField.getModelFile.returns({ getType: getType });
 
+            sandbox.restore();
+            sandbox.stub(ModelUtil, 'isMap').callsFake(() => {
+                return true;
+            });
+            sandbox.stub(ModelUtil, 'isScalar').callsFake(() => {
+                return false;
+            });
 
             let mockMapDeclaration      = sinon.createStubInstance(MapDeclaration);
+            let modelFile               = sinon.createStubInstance(ModelFile);
             const getKeyType            = sinon.stub();
             const getValueType          = sinon.stub();
 
+            mockField.getModelFile.returns(modelFile);
+            modelFile.getType.returns(mockMapDeclaration);
+
             getType.returns(mockMapDeclaration);
             getKeyType.returns('String');
             getValueType.returns('Concept');
@@ -1558,6 +1574,40 @@ public class SampleModel : Concept {
             mockField.dummy = 'Dummy Value';
             mockField.getModelFile.returns({ getType: getType });
 
+            sandbox.restore();
+            sandbox.stub(ModelUtil, 'isMap').callsFake(() => {
+                return true;
+            });
+
+            let mockMapDeclaration      = sinon.createStubInstance(MapDeclaration);
+            const getKeyType            = sinon.stub();
+            const getValueType          = sinon.stub();
+
+            getType.returns(mockMapDeclaration);
+            getKeyType.returns('String');
+            getValueType.returns('DateTime');
+            mockField.getName.returns('Map1');
+            mockMapDeclaration.getName.returns('Map1');
+            mockMapDeclaration.isMapDeclaration.returns(true);
+            mockMapDeclaration.getKey.returns({ getType: getKeyType });
+            mockMapDeclaration.getValue.returns({ getType: getValueType });
+
+            csharpVisitor.visitField(mockField, param);
+            param.fileWriter.writeLine.withArgs(1, 'public Dictionary<string, System.DateTime> Map1 { get; set; }').calledOnce.should.be.ok;
+        });
+
+        it('should write a line for field name and type thats a map of <SSN, DateTime>', () => {
+            const mockField             = sinon.createStubInstance(Field);
+            const getType               = sinon.stub();
+
+            mockField.dummy = 'Dummy Value';
+            mockField.getModelFile.returns({ getType: getType });
+
+            sandbox.restore();
+            sandbox.stub(ModelUtil, 'isMap').callsFake(() => {
+                return true;
+            });
+
             let mockMapDeclaration      = sinon.createStubInstance(MapDeclaration);
             const getKeyType            = sinon.stub();
             const getValueType          = sinon.stub();
diff --git a/types/lib/codegen/fromcto/golang/golangvisitor.d.ts b/types/lib/codegen/fromcto/golang/golangvisitor.d.ts
index 5f350707..f8588223 100644
--- a/types/lib/codegen/fromcto/golang/golangvisitor.d.ts
+++ b/types/lib/codegen/fromcto/golang/golangvisitor.d.ts
@@ -99,11 +99,4 @@ declare class GoLangVisitor {
      * @private
      */
     private toGoPackageName;
-    /**
-     * Check if field is a Map Declaration
-     * @param {Field} field - the field being visited
-     * @return {boolean} true if field is a Map Declaration
-     * @private
-     */
-    private isMap;
 }