diff --git a/src/Compilers/CSharp/Portable/Operations/CSharpOperationFactory.cs b/src/Compilers/CSharp/Portable/Operations/CSharpOperationFactory.cs
index 94ef707af5ba09c0bf2297ebdddeefd14419c4b7..ad04b67ce37ae87b22a04a70bd8bf9964676cd0b 100644
--- a/src/Compilers/CSharp/Portable/Operations/CSharpOperationFactory.cs
+++ b/src/Compilers/CSharp/Portable/Operations/CSharpOperationFactory.cs
@@ -594,7 +594,9 @@ private IObjectOrCollectionInitializerOperation CreateBoundCollectionInitializer
 
         private IOperation CreateBoundObjectInitializerMemberOperation(BoundObjectInitializerMember boundObjectInitializerMember)
         {
-            Lazy<IOperation> instance = boundObjectInitializerMember.MemberSymbol.IsStatic ?
+            Symbol memberSymbol = boundObjectInitializerMember.MemberSymbol;
+
+            Lazy<IOperation> instance = memberSymbol?.IsStatic == true ?
                                             OperationFactory.NullOperation :
                                             new Lazy<IOperation>(() =>
                                                 new InstanceReferenceExpression(
@@ -609,17 +611,27 @@ private IOperation CreateBoundObjectInitializerMemberOperation(BoundObjectInitia
             Optional<object> constantValue = ConvertToOptional(boundObjectInitializerMember.ConstantValue);
             bool isImplicit = boundObjectInitializerMember.WasCompilerGenerated;
 
-            switch (boundObjectInitializerMember.MemberSymbol.Kind)
+            if ((object)memberSymbol == null)
+            {
+                Debug.Assert(boundObjectInitializerMember.Type.IsDynamic());
+
+                Lazy<ImmutableArray<IOperation>> arguments = new Lazy<ImmutableArray<IOperation>>(() => boundObjectInitializerMember.Arguments.SelectAsArray(n => Create(n)));
+                ImmutableArray<string> argumentNames = boundObjectInitializerMember.ArgumentNamesOpt.NullToEmpty();
+                ImmutableArray<RefKind> argumentRefKinds = boundObjectInitializerMember.ArgumentRefKindsOpt.NullToEmpty();
+                return new LazyDynamicIndexerAccessExpression(instance, arguments, argumentNames, argumentRefKinds, _semanticModel, syntax, type, constantValue, isImplicit);
+            }
+
+            switch (memberSymbol.Kind)
             {
                 case SymbolKind.Field:
-                    var field = (FieldSymbol)boundObjectInitializerMember.MemberSymbol;
+                    var field = (FieldSymbol)memberSymbol;
                     bool isDeclaration = false;
                     return new LazyFieldReferenceExpression(field, isDeclaration, instance, _semanticModel, syntax, type, constantValue, isImplicit);
                 case SymbolKind.Event:
-                    var eventSymbol = (EventSymbol)boundObjectInitializerMember.MemberSymbol;
+                    var eventSymbol = (EventSymbol)memberSymbol;
                     return new LazyEventReferenceExpression(eventSymbol, instance, _semanticModel, syntax, type, constantValue, isImplicit);
                 case SymbolKind.Property:
-                    var property = (PropertySymbol)boundObjectInitializerMember.MemberSymbol;
+                    var property = (PropertySymbol)memberSymbol;
                     Lazy<ImmutableArray<IArgumentOperation>> arguments;
                     if (!boundObjectInitializerMember.Arguments.Any())
                     {
diff --git a/src/Compilers/CSharp/Test/Semantic/IOperation/IOperationTests_IObjectCreationExpression.cs b/src/Compilers/CSharp/Test/Semantic/IOperation/IOperationTests_IObjectCreationExpression.cs
index 9334b471af2c6823e45f2970aa428fb3c27c4c09..bdba3371e89833fd69e49557b620ca8f66932542 100644
--- a/src/Compilers/CSharp/Test/Semantic/IOperation/IOperationTests_IObjectCreationExpression.cs
+++ b/src/Compilers/CSharp/Test/Semantic/IOperation/IOperationTests_IObjectCreationExpression.cs
@@ -604,5 +604,183 @@ public void M1()
 
             VerifyOperationTreeAndDiagnosticsForTest<ObjectCreationExpressionSyntax>(source, expectedOperationTree, expectedDiagnostics);
         }
+
+        [CompilerTrait(CompilerFeature.IOperation)]
+        [Fact]
+        [WorkItem(23154, "https://github.com/dotnet/roslyn/issues/23154")]
+        public void ObjectCreationWithDynamicMemberInitializer_01()
+        {
+            string source = @"
+#pragma warning disable 0169
+class A
+{
+    dynamic this[int x, int y]
+    {
+        get
+        {
+            return new A();
+        }
+    }
+
+    dynamic this[string x, string y]
+    {
+        get
+        {
+            throw null;
+        }
+    }
+
+    int X, Y, Z;
+
+    static void Main()
+    {
+        dynamic x = 1;
+        new A {/*<bind>*/[y: x, x: x] = { X = 1, Y = 1, Z = 1 }/*</bind>*/ };
+    }
+}
+";
+            string expectedOperationTree = @"
+IMemberInitializerOperation (OperationKind.MemberInitializer, Type: dynamic) (Syntax: '[y: x, x: x ...  1, Z = 1 }')
+  InitializedMember: 
+    IDynamicIndexerAccessOperation (OperationKind.DynamicIndexerAccess, Type: dynamic) (Syntax: '[y: x, x: x]')
+      Expression: 
+        IInstanceReferenceOperation (OperationKind.InstanceReference, Type: A, IsImplicit) (Syntax: '[y: x, x: x]')
+      Arguments(2):
+          ILocalReferenceOperation: x (OperationKind.LocalReference, Type: dynamic) (Syntax: 'x')
+          ILocalReferenceOperation: x (OperationKind.LocalReference, Type: dynamic) (Syntax: 'x')
+      ArgumentNames(2):
+        ""y""
+        ""x""
+      ArgumentRefKinds(0)
+  Initializer: 
+    IObjectOrCollectionInitializerOperation (OperationKind.ObjectOrCollectionInitializer, Type: dynamic) (Syntax: '{ X = 1, Y = 1, Z = 1 }')
+      Initializers(3):
+          ISimpleAssignmentOperation (OperationKind.SimpleAssignment, Type: dynamic) (Syntax: 'X = 1')
+            Left: 
+              IOperation:  (OperationKind.None, Type: null) (Syntax: 'X')
+            Right: 
+              ILiteralOperation (OperationKind.Literal, Type: System.Int32, Constant: 1) (Syntax: '1')
+          ISimpleAssignmentOperation (OperationKind.SimpleAssignment, Type: dynamic) (Syntax: 'Y = 1')
+            Left: 
+              IOperation:  (OperationKind.None, Type: null) (Syntax: 'Y')
+            Right: 
+              ILiteralOperation (OperationKind.Literal, Type: System.Int32, Constant: 1) (Syntax: '1')
+          ISimpleAssignmentOperation (OperationKind.SimpleAssignment, Type: dynamic) (Syntax: 'Z = 1')
+            Left: 
+              IOperation:  (OperationKind.None, Type: null) (Syntax: 'Z')
+            Right: 
+              ILiteralOperation (OperationKind.Literal, Type: System.Int32, Constant: 1) (Syntax: '1')
+";
+            var expectedDiagnostics = DiagnosticDescription.None;
+
+            VerifyOperationTreeAndDiagnosticsForTest<AssignmentExpressionSyntax>(source, expectedOperationTree, expectedDiagnostics);
+        }
+
+        [CompilerTrait(CompilerFeature.IOperation)]
+        [Fact]
+        [WorkItem(23154, "https://github.com/dotnet/roslyn/issues/23154")]
+        public void ObjectCreationWithDynamicMemberInitializer_02()
+        {
+            string source = @"
+#pragma warning disable 0169
+class A
+{
+    dynamic this[int x, int y]
+    {
+        get
+        {
+            return new A();
+        }
+    }
+
+    dynamic this[string x, string y]
+    {
+        get
+        {
+            throw null;
+        }
+    }
+
+    int X, Y, Z;
+
+    static void Main()
+    {
+        dynamic x = 1;
+        new A {/*<bind>*/[y: x, x: x] = { }/*</bind>*/ };
+    }
+}
+";
+            string expectedOperationTree = @"
+IMemberInitializerOperation (OperationKind.MemberInitializer, Type: dynamic) (Syntax: '[y: x, x: x] = { }')
+  InitializedMember: 
+    IDynamicIndexerAccessOperation (OperationKind.DynamicIndexerAccess, Type: dynamic) (Syntax: '[y: x, x: x]')
+      Expression: 
+        IInstanceReferenceOperation (OperationKind.InstanceReference, Type: A, IsImplicit) (Syntax: '[y: x, x: x]')
+      Arguments(2):
+          ILocalReferenceOperation: x (OperationKind.LocalReference, Type: dynamic) (Syntax: 'x')
+          ILocalReferenceOperation: x (OperationKind.LocalReference, Type: dynamic) (Syntax: 'x')
+      ArgumentNames(2):
+        ""y""
+        ""x""
+      ArgumentRefKinds(0)
+  Initializer: 
+    IObjectOrCollectionInitializerOperation (OperationKind.ObjectOrCollectionInitializer, Type: dynamic) (Syntax: '{ }')
+      Initializers(0)
+";
+            var expectedDiagnostics = DiagnosticDescription.None;
+
+            VerifyOperationTreeAndDiagnosticsForTest<AssignmentExpressionSyntax>(source, expectedOperationTree, expectedDiagnostics);
+        }
+
+        [CompilerTrait(CompilerFeature.IOperation)]
+        [Fact]
+        [WorkItem(23154, "https://github.com/dotnet/roslyn/issues/23154")]
+        public void ObjectCreationWithDynamicMemberInitializer_03()
+        {
+            string source = @"
+#pragma warning disable 0169
+class A
+{
+    dynamic this[int x, int y]
+    {
+        get
+        {
+            return new A();
+        }
+    }
+
+    dynamic this[string x, string y]
+    {
+        get
+        {
+            throw null;
+        }
+    }
+
+    int X, Y, Z;
+
+    static void Main()
+    {
+        dynamic x = 1;
+        new A {/*<bind>*/[y: x, x: x]/*</bind>*/ = { } };
+    }
+}
+";
+            string expectedOperationTree = @"
+IDynamicIndexerAccessOperation (OperationKind.DynamicIndexerAccess, Type: dynamic) (Syntax: '[y: x, x: x]')
+  Expression: 
+    IInstanceReferenceOperation (OperationKind.InstanceReference, Type: A, IsImplicit) (Syntax: '[y: x, x: x]')
+  Arguments(2):
+      ILocalReferenceOperation: x (OperationKind.LocalReference, Type: dynamic) (Syntax: 'x')
+      ILocalReferenceOperation: x (OperationKind.LocalReference, Type: dynamic) (Syntax: 'x')
+  ArgumentNames(2):
+    ""y""
+    ""x""
+  ArgumentRefKinds(0)
+";
+            var expectedDiagnostics = DiagnosticDescription.None;
+
+            VerifyOperationTreeAndDiagnosticsForTest<ExpressionSyntax>(source, expectedOperationTree, expectedDiagnostics);
+        }
     }
 }
diff --git a/src/VisualStudio/CSharp/Impl/CodeModel/CSharpCodeModelService.cs b/src/VisualStudio/CSharp/Impl/CodeModel/CSharpCodeModelService.cs
index ae8eea9f642c5c59ea794d65b38d57aa1c449c1f..35bccf4c0983a29c95cbb3a7646dc753ebdd038f 100644
--- a/src/VisualStudio/CSharp/Impl/CodeModel/CSharpCodeModelService.cs
+++ b/src/VisualStudio/CSharp/Impl/CodeModel/CSharpCodeModelService.cs
@@ -879,6 +879,9 @@ public override SyntaxNode SetName(SyntaxNode node, string name)
                 throw new ArgumentNullException(nameof(node));
             }
 
+            // In all cases, the resulting syntax for the new name has elastic trivia attached,
+            // whether via this call to SyntaxFactory.Identifier or via explicitly added elastic
+            // markers.
             SyntaxToken newIdentifier = SyntaxFactory.Identifier(name);
             switch (node.Kind())
             {
@@ -904,13 +907,19 @@ public override SyntaxNode SetName(SyntaxNode node, string name)
                 case SyntaxKind.Parameter:
                     return ((ParameterSyntax)node).WithIdentifier(newIdentifier);
                 case SyntaxKind.NamespaceDeclaration:
-                    return ((NamespaceDeclarationSyntax)node).WithName(SyntaxFactory.IdentifierName(name));
+                    return ((NamespaceDeclarationSyntax)node).WithName(
+                        SyntaxFactory.ParseName(name)
+                            .WithLeadingTrivia(SyntaxFactory.TriviaList(SyntaxFactory.ElasticMarker))
+                            .WithTrailingTrivia(SyntaxFactory.TriviaList(SyntaxFactory.ElasticMarker)));
                 case SyntaxKind.EnumMemberDeclaration:
                     return ((EnumMemberDeclarationSyntax)node).WithIdentifier(newIdentifier);
                 case SyntaxKind.VariableDeclarator:
                     return ((VariableDeclaratorSyntax)node).WithIdentifier(newIdentifier);
                 case SyntaxKind.Attribute:
-                    return ((AttributeSyntax)node).WithName(SyntaxFactory.IdentifierName(name));
+                    return ((AttributeSyntax)node).WithName(
+                        SyntaxFactory.ParseName(name)
+                            .WithLeadingTrivia(SyntaxFactory.TriviaList(SyntaxFactory.ElasticMarker))
+                            .WithTrailingTrivia(SyntaxFactory.TriviaList(SyntaxFactory.ElasticMarker)));
                 case SyntaxKind.AttributeArgument:
                     return ((AttributeArgumentSyntax)node).WithNameEquals(SyntaxFactory.NameEquals(SyntaxFactory.IdentifierName(name)));
                 default:
diff --git a/src/VisualStudio/Core/Test/CodeModel/AbstractCodeNamespaceTests.vb b/src/VisualStudio/Core/Test/CodeModel/AbstractCodeNamespaceTests.vb
index 18433eef05b54432c87e62eb16a4d8fe5596f73b..127b4c66e5bb3e35ba96e46237d352dad0dfb41b 100644
--- a/src/VisualStudio/Core/Test/CodeModel/AbstractCodeNamespaceTests.vb
+++ b/src/VisualStudio/Core/Test/CodeModel/AbstractCodeNamespaceTests.vb
@@ -41,7 +41,7 @@ Namespace Microsoft.VisualStudio.LanguageServices.UnitTests.CodeModel
         End Function
 
         Protected Overrides Function GetNameSetter(codeElement As EnvDTE.CodeNamespace) As Action(Of String)
-            Throw New NotImplementedException()
+            Return Sub(name) codeElement.Name = name
         End Function
 
         Protected Overrides Function GetParent(codeElement As EnvDTE.CodeNamespace) As Object
diff --git a/src/VisualStudio/Core/Test/CodeModel/CSharp/CodeAttributeTests.vb b/src/VisualStudio/Core/Test/CodeModel/CSharp/CodeAttributeTests.vb
index 338f40cf8e6eabd104c769022ca60c6ef7878f31..f67c59ad424681834176a09d43a417e9d06cbce4 100644
--- a/src/VisualStudio/Core/Test/CodeModel/CSharp/CodeAttributeTests.vb
+++ b/src/VisualStudio/Core/Test/CodeModel/CSharp/CodeAttributeTests.vb
@@ -861,7 +861,7 @@ class CAttribute : Attribute { }
 
 #Region "Set Name tests"
         <ConditionalWpfFact(GetType(x86)), Trait(Traits.Feature, Traits.Features.CodeModel)>
-        Public Async Function TestSetName1() As Task
+        Public Async Function TestSetName_NewName() As Task
             Dim code =
 <Code>
 [$$Goo]
@@ -876,6 +876,40 @@ class C { }
 
             Await TestSetName(code, expected, "Bar", NoThrow(Of String)())
         End Function
+
+        <ConditionalWpfFact(GetType(x86)), Trait(Traits.Feature, Traits.Features.CodeModel)>
+        Public Async Function TestSetName_SimpleNameToDottedName() As Task
+            Dim code =
+<Code>
+[$$Goo]
+class C { }
+</Code>
+
+            Dim expected =
+<Code>
+[Bar.Baz]
+class C { }
+</Code>
+
+            Await TestSetName(code, expected, "Bar.Baz", NoThrow(Of String)())
+        End Function
+
+        <ConditionalWpfFact(GetType(x86)), Trait(Traits.Feature, Traits.Features.CodeModel)>
+        Public Async Function TestSetName_DottedNameToSimpleName() As Task
+            Dim code =
+<Code>
+[$$Goo.Bar]
+class C { }
+</Code>
+
+            Dim expected =
+<Code>
+[Baz]
+class C { }
+</Code>
+
+            Await TestSetName(code, expected, "Baz", NoThrow(Of String)())
+        End Function
 #End Region
 
 #Region "Set Target tests"
diff --git a/src/VisualStudio/Core/Test/CodeModel/CSharp/CodeNamespaceTests.vb b/src/VisualStudio/Core/Test/CodeModel/CSharp/CodeNamespaceTests.vb
index e637e51e7464bb05eb5302a293cc111221c03163..cc0128adc6b27accc7b0d2ab45105421f0325cdb 100644
--- a/src/VisualStudio/Core/Test/CodeModel/CSharp/CodeNamespaceTests.vb
+++ b/src/VisualStudio/Core/Test/CodeModel/CSharp/CodeNamespaceTests.vb
@@ -389,6 +389,109 @@ namespace N1
 
 #End Region
 
+#Region "Set Name tests"
+        <ConditionalWpfFact(GetType(x86)), Trait(Traits.Feature, Traits.Features.CodeModel)>
+        Public Async Function TestSetName_SameName() As Task
+            Dim code =
+<Code><![CDATA[
+namespace N$$ 
+{
+    class C
+    {
+    }
+}
+]]></Code>
+
+            Dim expected =
+<Code><![CDATA[
+namespace N
+{
+    class C
+    {
+    }
+}
+]]></Code>
+
+            Await TestSetName(code, expected, "N", NoThrow(Of String)())
+        End Function
+
+        <ConditionalWpfFact(GetType(x86)), Trait(Traits.Feature, Traits.Features.CodeModel)>
+        Public Async Function TestSetName_NewName() As Task
+            Dim code =
+<Code><![CDATA[
+namespace N$$
+{
+    class C
+    {
+    }
+}
+]]></Code>
+
+            Dim expected =
+<Code><![CDATA[
+namespace N2
+{
+    class C
+    {
+    }
+}
+]]></Code>
+
+            Await TestSetName(code, expected, "N2", NoThrow(Of String)())
+        End Function
+
+        <ConditionalWpfFact(GetType(x86)), Trait(Traits.Feature, Traits.Features.CodeModel)>
+        Public Async Function TestSetName_SimpleNameToDottedName() As Task
+            Dim code =
+<Code><![CDATA[
+namespace N1$$
+{
+    class C
+    {
+    }
+}
+]]></Code>
+
+            Dim expected =
+<Code><![CDATA[
+namespace N2.N3
+{
+    class C
+    {
+    }
+}
+]]></Code>
+
+            Await TestSetName(code, expected, "N2.N3", NoThrow(Of String)())
+        End Function
+
+        <ConditionalWpfFact(GetType(x86)), Trait(Traits.Feature, Traits.Features.CodeModel)>
+        Public Async Function TestSetName_DottedNameToSimpleName() As Task
+            Dim code =
+<Code><![CDATA[
+namespace N1.N2$$
+{
+    class C
+    {
+    }
+}
+]]></Code>
+
+            Dim expected =
+<Code><![CDATA[
+namespace N3.N4
+{
+    class C
+    {
+    }
+}
+]]></Code>
+
+            Await TestSetName(code, expected, "N3.N4", NoThrow(Of String)())
+        End Function
+
+#End Region
+
 #Region "Remove tests"
 
         <ConditionalWpfFact(GetType(x86)), Trait(Traits.Feature, Traits.Features.CodeModel)>
diff --git a/src/VisualStudio/Core/Test/CodeModel/VisualBasic/CodeAttributeTests.vb b/src/VisualStudio/Core/Test/CodeModel/VisualBasic/CodeAttributeTests.vb
index 9cac7be17662c618c8f56e0aa2734cb2d238d60e..7a08444a61e3356e97c00c95c3d6010ec69039b1 100644
--- a/src/VisualStudio/Core/Test/CodeModel/VisualBasic/CodeAttributeTests.vb
+++ b/src/VisualStudio/Core/Test/CodeModel/VisualBasic/CodeAttributeTests.vb
@@ -1065,7 +1065,7 @@ End Class
 
 #Region "Set Name tests"
         <ConditionalWpfFact(GetType(x86)), Trait(Traits.Feature, Traits.Features.CodeModel)>
-        Public Async Function TestSetName1() As Task
+        Public Async Function TestSetName_NewName() As Task
             Dim code =
 <Code><![CDATA[
 <$$Goo()>
@@ -1082,6 +1082,44 @@ End Class
 
             Await TestSetName(code, expected, "Bar", NoThrow(Of String)())
         End Function
+
+        <ConditionalWpfFact(GetType(x86)), Trait(Traits.Feature, Traits.Features.CodeModel)>
+        Public Async Function TestSetName_SimpleNameToDottedName() As Task
+            Dim code =
+<Code><![CDATA[
+<$$Goo()>
+Class C
+End Class
+]]></Code>
+
+            Dim expected =
+<Code><![CDATA[
+<Bar.Baz()>
+Class C
+End Class
+]]></Code>
+
+            Await TestSetName(code, expected, "Bar.Baz", NoThrow(Of String)())
+        End Function
+
+        <ConditionalWpfFact(GetType(x86)), Trait(Traits.Feature, Traits.Features.CodeModel)>
+        Public Async Function TestSetName_DottedNameToSimpleName() As Task
+            Dim code =
+<Code><![CDATA[
+<$$Goo()>
+Class C
+End Class
+]]></Code>
+
+            Dim expected =
+<Code><![CDATA[
+<Bar.Baz()>
+Class C
+End Class
+]]></Code>
+
+            Await TestSetName(code, expected, "Bar.Baz", NoThrow(Of String)())
+        End Function
 #End Region
 
 #Region "Set Target tests"
diff --git a/src/VisualStudio/Core/Test/CodeModel/VisualBasic/CodeNamespaceTests.vb b/src/VisualStudio/Core/Test/CodeModel/VisualBasic/CodeNamespaceTests.vb
index 4dc91058a9837c8cce645b9c242bed7c53129072..15c6aa339657f8ff7aabe1d387cb73cdebf0d90c 100644
--- a/src/VisualStudio/Core/Test/CodeModel/VisualBasic/CodeNamespaceTests.vb
+++ b/src/VisualStudio/Core/Test/CodeModel/VisualBasic/CodeNamespaceTests.vb
@@ -821,6 +821,94 @@ End Namespace
 
 #End Region
 
+#Region "Set Name tests"
+
+        <ConditionalWpfFact(GetType(x86)), Trait(Traits.Feature, Traits.Features.CodeModel)>
+        Public Async Function TestSetName_SameName() As Task
+            Dim code =
+<Code>
+Namespace N$$
+    Class C
+    End Class
+End Namespace
+</Code>
+
+            Dim expected =
+<Code>
+Namespace N
+    Class C
+    End Class
+End Namespace
+</Code>
+
+            Await TestSetName(code, expected, "N", NoThrow(Of String)())
+        End Function
+
+        <ConditionalWpfFact(GetType(x86)), Trait(Traits.Feature, Traits.Features.CodeModel)>
+        Public Async Function TestSetName_NewName() As Task
+            Dim code =
+<Code>
+Namespace N$$
+    Class C
+    End Class
+End Namespace
+</Code>
+
+            Dim expected =
+<Code>
+Namespace N2
+    Class C
+    End Class
+End Namespace
+</Code>
+
+            Await TestSetName(code, expected, "N2", NoThrow(Of String)())
+        End Function
+
+        <ConditionalWpfFact(GetType(x86)), Trait(Traits.Feature, Traits.Features.CodeModel)>
+        Public Async Function TestSetName_SimpleNameToDottedName() As Task
+            Dim code =
+<Code>
+Namespace N1$$
+    Class C
+    End Class
+End Namespace
+</Code>
+
+            Dim expected =
+<Code>
+Namespace N2.N3
+    Class C
+    End Class
+End Namespace
+</Code>
+
+            Await TestSetName(code, expected, "N2.N3", NoThrow(Of String)())
+        End Function
+
+        <ConditionalWpfFact(GetType(x86)), Trait(Traits.Feature, Traits.Features.CodeModel)>
+        Public Async Function TestSetName_DottedNameToDottedName() As Task
+            Dim code =
+<Code>
+Namespace N1.N2$$
+    Class C
+    End Class
+End Namespace
+</Code>
+
+            Dim expected =
+<Code>
+Namespace N3.N4
+    Class C
+    End Class
+End Namespace
+</Code>
+
+            Await TestSetName(code, expected, "N3.N4", NoThrow(Of String)())
+        End Function
+
+#End Region
+
 #Region "Remove tests"
 
         <ConditionalWpfFact(GetType(x86)), Trait(Traits.Feature, Traits.Features.CodeModel)>
diff --git a/src/VisualStudio/VisualBasic/Impl/CodeModel/VisualBasicCodeModelService.vb b/src/VisualStudio/VisualBasic/Impl/CodeModel/VisualBasicCodeModelService.vb
index f7cd42a8c3b41135b6cab06801e7386da955bb1f..8cedc9c96ce01f2b8b5852a7dc1b541e2421714a 100644
--- a/src/VisualStudio/VisualBasic/Impl/CodeModel/VisualBasicCodeModelService.vb
+++ b/src/VisualStudio/VisualBasic/Impl/CodeModel/VisualBasicCodeModelService.vb
@@ -941,11 +941,17 @@ Namespace Microsoft.VisualStudio.LanguageServices.VisualBasic.CodeModel
                 Throw New ArgumentNullException(NameOf(node))
             End If
 
+            ' In all cases, the resulting syntax for the new name has elastic trivia attached,
+            ' whether via this call to SyntaxFactory.Identifier or via explicitly added elastic
+            ' markers.
             Dim identifier As SyntaxToken = SyntaxFactory.Identifier(name)
 
             Select Case node.Kind
                 Case SyntaxKind.Attribute
-                    Return DirectCast(node, AttributeSyntax).WithName(SyntaxFactory.ParseTypeName(name))
+                    Return DirectCast(node, AttributeSyntax).WithName(
+                        SyntaxFactory.ParseTypeName(name) _
+                            .WithLeadingTrivia(SyntaxFactory.TriviaList(SyntaxFactory.ElasticMarker)) _
+                            .WithTrailingTrivia(SyntaxFactory.TriviaList(SyntaxFactory.ElasticMarker)))
                 Case SyntaxKind.ClassStatement
                     Return DirectCast(node, ClassStatementSyntax).WithIdentifier(identifier)
                 Case SyntaxKind.InterfaceStatement
@@ -960,7 +966,10 @@ Namespace Microsoft.VisualStudio.LanguageServices.VisualBasic.CodeModel
                      SyntaxKind.DelegateSubStatement
                     Return DirectCast(node, DelegateStatementSyntax).WithIdentifier(identifier)
                 Case SyntaxKind.NamespaceStatement
-                    Return DirectCast(node, NamespaceStatementSyntax).WithName(SyntaxFactory.ParseName(name))
+                    Return DirectCast(node, NamespaceStatementSyntax).WithName(
+                        SyntaxFactory.ParseName(name) _
+                            .WithLeadingTrivia(SyntaxFactory.TriviaList(SyntaxFactory.ElasticMarker)) _
+                            .WithTrailingTrivia(SyntaxFactory.TriviaList(SyntaxFactory.ElasticMarker)))
                 Case SyntaxKind.SubStatement,
                      SyntaxKind.FunctionStatement,
                      SyntaxKind.SubNewStatement