diff --git a/src/Microsoft.SqlTools.ServiceLayer/Formatter/TSqlFormatterService.cs b/src/Microsoft.SqlTools.ServiceLayer/Formatter/TSqlFormatterService.cs
index f13b9e2f..61bea2dd 100644
--- a/src/Microsoft.SqlTools.ServiceLayer/Formatter/TSqlFormatterService.cs
+++ b/src/Microsoft.SqlTools.ServiceLayer/Formatter/TSqlFormatterService.cs
@@ -53,6 +53,13 @@ namespace Microsoft.SqlTools.ServiceLayer.Formatter
             get { return ServiceProvider.GetService<WorkspaceService<SqlToolsSettings>>(); }
         }
 
+        /// <summary>
+        /// Gets the language service. Note: should handle case where this is null in cases where unit tests do not set this up
+        /// </summary>
+        private LanguageService LanguageService
+        {
+            get { return ServiceProvider.GetService<LanguageService>(); }
+        }
 
         /// <summary>
         /// Ensure formatter settings are always up to date
@@ -105,6 +112,11 @@ namespace Microsoft.SqlTools.ServiceLayer.Formatter
         {
             return await Task.Factory.StartNew(() =>
             {
+                if (ShouldSkipFormatting(docFormatParams))
+                {
+                    return Array.Empty<TextEdit>();
+                }
+
                 var range = docFormatParams.Range;
                 ScriptFile scriptFile = GetFile(docFormatParams);
                 if (scriptFile == null)
@@ -117,10 +129,26 @@ namespace Microsoft.SqlTools.ServiceLayer.Formatter
             });
         }
 
-        private async Task<TextEdit[]> FormatAndReturnEdits(DocumentFormattingParams docFormatParams)
+        private bool ShouldSkipFormatting(DocumentFormattingParams docFormatParams)
         {
+            if (docFormatParams == null
+                || docFormatParams.TextDocument == null
+                || docFormatParams.TextDocument.Uri == null)
+            {
+                return true;
+            }
+            return (LanguageService != null && LanguageService.ShouldSkipNonMssqlFile(docFormatParams.TextDocument.Uri));
+        }
+
+        private async Task<TextEdit[]> FormatAndReturnEdits(DocumentFormattingParams docFormatParams)
+        {            
             return await Task.Factory.StartNew(() =>
             {
+                if (ShouldSkipFormatting(docFormatParams))
+                {
+                    return Array.Empty<TextEdit>();
+                }
+
                 var scriptFile = GetFile(docFormatParams);
                 if (scriptFile == null
                     || scriptFile.FileLines.Count == 0)
diff --git a/src/Microsoft.SqlTools.ServiceLayer/LanguageServices/LanguageService.cs b/src/Microsoft.SqlTools.ServiceLayer/LanguageServices/LanguageService.cs
index c5097fe7..91994a50 100644
--- a/src/Microsoft.SqlTools.ServiceLayer/LanguageServices/LanguageService.cs
+++ b/src/Microsoft.SqlTools.ServiceLayer/LanguageServices/LanguageService.cs
@@ -36,7 +36,7 @@ namespace Microsoft.SqlTools.ServiceLayer.LanguageServices
     /// Main class for Language Service functionality including anything that requires knowledge of
     /// the language to perform, such as definitions, intellisense, etc.
     /// </summary>
-    public sealed class LanguageService: IDisposable
+    public class LanguageService: IDisposable
     {
         #region Singleton Instance Implementation
 
@@ -960,7 +960,11 @@ namespace Microsoft.SqlTools.ServiceLayer.LanguageServices
             return ShouldSkipNonMssqlFile(scriptFile.ClientFilePath);
         }
 
-        private bool ShouldSkipNonMssqlFile(string uri)
+        /// <summary>
+        /// Checks if a given URI is not an MSSQL file. Only files explicitly excluded by a language flavor change
+        /// notification will be treated as skippable
+        /// </summary>
+        public virtual bool ShouldSkipNonMssqlFile(string uri)
         {
             bool isNonMssql = false;
             nonMssqlUriMap.TryGetValue(uri, out isNonMssql);
diff --git a/test/Microsoft.SqlTools.ServiceLayer.UnitTests/Formatter/FormatterUnitTestBase.cs b/test/Microsoft.SqlTools.ServiceLayer.UnitTests/Formatter/FormatterUnitTestBase.cs
index 79e01577..8cefa3ba 100644
--- a/test/Microsoft.SqlTools.ServiceLayer.UnitTests/Formatter/FormatterUnitTestBase.cs
+++ b/test/Microsoft.SqlTools.ServiceLayer.UnitTests/Formatter/FormatterUnitTestBase.cs
@@ -8,6 +8,7 @@ using System.Reflection;
 using Microsoft.SqlTools.Hosting.Protocol;
 using Microsoft.SqlTools.Extensibility;
 using Microsoft.SqlTools.ServiceLayer.Formatter;
+using Microsoft.SqlTools.ServiceLayer.LanguageServices;
 using Microsoft.SqlTools.ServiceLayer.SqlContext;
 using Microsoft.SqlTools.ServiceLayer.Test.Common;
 using Microsoft.SqlTools.ServiceLayer.Workspace;
@@ -21,8 +22,10 @@ namespace Microsoft.SqlTools.ServiceLayer.UnitTests.Formatter
         {
             HostMock = new Mock<IProtocolEndpoint>();
             WorkspaceServiceMock = new Mock<WorkspaceService<SqlToolsSettings>>();
+            LanguageServiceMock = new Mock<LanguageService>();
             ServiceProvider = ExtensionServiceProvider.CreateDefaultServiceProvider();
             ServiceProvider.RegisterSingleService(WorkspaceServiceMock.Object);
+            ServiceProvider.RegisterSingleService(LanguageServiceMock.Object);
             HostLoader.InitializeHostedServices(ServiceProvider, HostMock.Object);
             FormatterService = ServiceProvider.GetService<TSqlFormatterService>();
         }
@@ -30,6 +33,7 @@ namespace Microsoft.SqlTools.ServiceLayer.UnitTests.Formatter
         protected ExtensionServiceProvider ServiceProvider { get; private set; }
         protected Mock<IProtocolEndpoint> HostMock { get; private set; }
         protected Mock<WorkspaceService<SqlToolsSettings>> WorkspaceServiceMock { get; private set; }
+        protected Mock<LanguageService> LanguageServiceMock { get; private set; }
 
         protected TSqlFormatterService FormatterService { get; private set; }
 
diff --git a/test/Microsoft.SqlTools.ServiceLayer.UnitTests/Formatter/TSqlFormatterServiceTests.cs b/test/Microsoft.SqlTools.ServiceLayer.UnitTests/Formatter/TSqlFormatterServiceTests.cs
index 135d618f..49443eb1 100644
--- a/test/Microsoft.SqlTools.ServiceLayer.UnitTests/Formatter/TSqlFormatterServiceTests.cs
+++ b/test/Microsoft.SqlTools.ServiceLayer.UnitTests/Formatter/TSqlFormatterServiceTests.cs
@@ -9,6 +9,7 @@ using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.SqlTools.Hosting.Protocol;
 using Microsoft.SqlTools.ServiceLayer.Formatter.Contracts;
+using Microsoft.SqlTools.ServiceLayer.LanguageServices;
 using Microsoft.SqlTools.ServiceLayer.LanguageServices.Contracts;
 using Microsoft.SqlTools.ServiceLayer.Test.Common;
 using Microsoft.SqlTools.ServiceLayer.UnitTests.Utility;
@@ -57,10 +58,16 @@ namespace Microsoft.SqlTools.ServiceLayer.UnitTests.Formatter
     C2 nvarchar(50) NULL
 )");
         
+        private void SetupLanguageService(bool skipFile = false)
+        {
+            LanguageServiceMock.Setup(x => x.ShouldSkipNonMssqlFile(It.IsAny<string>())).Returns(skipFile);
+        }
+
         [Fact]
         public async Task FormatDocumentShouldReturnSingleEdit()
         {
             // Given a document that we want to format
+            SetupLanguageService();
             SetupScriptFile(defaultSqlContents);
             // When format document is called
             await TestUtils.RunAndVerify<TextEdit[]>(
@@ -73,12 +80,64 @@ namespace Microsoft.SqlTools.ServiceLayer.UnitTests.Formatter
                 }));
         }
 
+        [Fact]
+        public async Task FormatDocumentShouldSkipNonMssqlFile()
+        {
+            // Given a non-MSSQL document
+            SetupLanguageService(skipFile: true);
+            SetupScriptFile(defaultSqlContents);
+            // When format document is called
+            await TestUtils.RunAndVerify<TextEdit[]>(
+                test: (requestContext) => FormatterService.HandleDocFormatRequest(docFormatParams, requestContext),
+                verify: (edits =>
+                {
+                    // Then expect a single edit to be returned and for it to match the standard formatting
+                    Assert.Equal(0, edits.Length);
+                    LanguageServiceMock.Verify(x => x.ShouldSkipNonMssqlFile(docFormatParams.TextDocument.Uri), Times.Once);
+                }));
+        }
+
+        [Fact]
+        public async Task FormatRangeShouldReturnSingleEdit()
+        {
+            // Given a document that we want to format
+            SetupLanguageService();
+            SetupScriptFile(defaultSqlContents);
+            // When format document is called
+            await TestUtils.RunAndVerify<TextEdit[]>(
+                test: (requestContext) => FormatterService.HandleDocRangeFormatRequest(rangeFormatParams, requestContext),
+                verify: (edits =>
+                {
+                    // Then expect a single edit to be returned and for it to match the standard formatting
+                    Assert.Equal(1, edits.Length);
+                    AssertFormattingEqual(formattedSqlContents, edits[0].NewText);
+                }));
+        }
+
+        [Fact]
+        public async Task FormatRangeShouldSkipNonMssqlFile()
+        {
+            // Given a non-MSSQL document
+            SetupLanguageService(skipFile: true);
+            SetupScriptFile(defaultSqlContents);
+            // When format document is called
+            await TestUtils.RunAndVerify<TextEdit[]>(
+                test: (requestContext) => FormatterService.HandleDocRangeFormatRequest(rangeFormatParams, requestContext),
+                verify: (edits =>
+                {
+                    // Then expect a single edit to be returned and for it to match the standard formatting
+                    Assert.Equal(0, edits.Length);
+                    LanguageServiceMock.Verify(x => x.ShouldSkipNonMssqlFile(docFormatParams.TextDocument.Uri), Times.Once);
+                }));
+        }
+
+
         [Fact]
         public async Task FormatDocumentTelemetryShouldIncludeFormatTypeProperty()
         {
             await RunAndVerifyTelemetryTest(
                 // Given a document that we want to format
-                preRunSetup: () => SetupScriptFile(defaultSqlContents),
+                preRunSetup: () => SetupLanguageService(),
                 // When format document is called
                 test: (requestContext) => FormatterService.HandleDocFormatRequest(docFormatParams, requestContext),
                 verify: (result, actualParams) =>
@@ -95,7 +154,7 @@ namespace Microsoft.SqlTools.ServiceLayer.UnitTests.Formatter
         {
             await RunAndVerifyTelemetryTest(
                 // Given a document that we want to format
-                preRunSetup: () => SetupScriptFile(defaultSqlContents),
+                preRunSetup: () => SetupLanguageService(),
                 // When format range is called
                 test: (requestContext) => FormatterService.HandleDocRangeFormatRequest(rangeFormatParams, requestContext),
                 verify: (result, actualParams) =>
@@ -131,6 +190,10 @@ namespace Microsoft.SqlTools.ServiceLayer.UnitTests.Formatter
             });
 
             // Given a document that we want to format
+            if (preRunSetup != null)
+            {
+                preRunSetup();
+            }
             SetupScriptFile(defaultSqlContents);
 
             // When format document is called