diff --git a/src/EditorFeatures/Core/FindUsages/AbstractFindUsagesService.cs b/src/EditorFeatures/Core/FindUsages/AbstractFindUsagesService.cs
index 2c6157b396c775d5aa706d22663969797d08d4b7..ae61b9445efa1f633d15de8026f1d52985c1e54d 100644
--- a/src/EditorFeatures/Core/FindUsages/AbstractFindUsagesService.cs
+++ b/src/EditorFeatures/Core/FindUsages/AbstractFindUsagesService.cs
@@ -2,6 +2,8 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+#nullable enable
+
 using System;
 using System.Collections.Immutable;
 using System.Linq;
@@ -12,6 +14,7 @@
 using Microsoft.CodeAnalysis.FindUsages;
 using Microsoft.CodeAnalysis.LanguageServices;
 using Microsoft.CodeAnalysis.Shared.Extensions;
+using Microsoft.CodeAnalysis.SymbolMonikers;
 using Roslyn.Utilities;
 using VS.IntelliNav.Contracts;
 
@@ -20,10 +23,14 @@ namespace Microsoft.CodeAnalysis.Editor.FindUsages
     internal abstract partial class AbstractFindUsagesService : IFindUsagesService
     {
         private readonly IThreadingContext _threadingContext;
+        private readonly ICodeIndexProvider? _codeIndexProvider;
 
-        protected AbstractFindUsagesService(IThreadingContext threadingContext)
+        protected AbstractFindUsagesService(
+            IThreadingContext threadingContext,
+            ICodeIndexProvider? codeIndexProvider)
         {
             _threadingContext = threadingContext;
+            _codeIndexProvider = codeIndexProvider;
         }
 
         public async Task FindImplementationsAsync(
@@ -111,7 +118,7 @@ protected AbstractFindUsagesService(IThreadingContext threadingContext)
             ImmutableArray<DefinitionItem> definitions,
             CancellationToken cancellationToken)
         {
-            var factory = solution.Workspace.Services.GetService<IDefinitionsAndReferencesFactory>();
+            var factory = solution.Workspace.Services.GetRequiredService<IDefinitionsAndReferencesFactory>();
             return definitions.Select(d => factory.GetThirdPartyDefinitionItem(solution, d, cancellationToken))
                               .WhereNotNull()
                               .ToImmutableArray();
@@ -127,13 +134,11 @@ protected AbstractFindUsagesService(IThreadingContext threadingContext)
             var symbolAndProject = await FindUsagesHelpers.GetRelevantSymbolAndProjectAtPositionAsync(
                 document, position, cancellationToken).ConfigureAwait(false);
             if (symbolAndProject == null)
-            {
                 return;
-            }
 
             await FindSymbolReferencesAsync(
-                _threadingContext,
-                context, symbolAndProject?.symbol, symbolAndProject?.project, cancellationToken).ConfigureAwait(false);
+                _threadingContext, _codeIndexProvider, context,
+                symbolAndProject.Value.symbol, symbolAndProject.Value.project, cancellationToken).ConfigureAwait(false);
         }
 
         /// <summary>
@@ -141,7 +146,7 @@ protected AbstractFindUsagesService(IThreadingContext threadingContext)
         /// and want to push all the references to it into the Streaming-Find-References window.
         /// </summary>
         public static async Task FindSymbolReferencesAsync(
-            IThreadingContext threadingContext,
+            IThreadingContext threadingContext, ICodeIndexProvider? codeIndexProvider,
             IFindUsagesContext context, ISymbol symbol, Project project, CancellationToken cancellationToken)
         {
             await context.SetSearchTitleAsync(string.Format(EditorFeaturesResources._0_references,
@@ -154,14 +159,53 @@ protected AbstractFindUsagesService(IThreadingContext threadingContext)
             // engine will push results into the 'progress' instance passed into it.
             // We'll take those results, massage them, and forward them along to the 
             // FindReferencesContext instance we were given.
-            await SymbolFinder.FindReferencesAsync(
+            var normalFindReferencesTask = SymbolFinder.FindReferencesAsync(
                 SymbolAndProjectId.Create(symbol, project.Id),
                 project.Solution,
                 progressAdapter,
                 documents: null,
-                options: options,
-                cancellationToken: cancellationToken).ConfigureAwait(false);
-            ICodeIndexProvider
+                options,
+                cancellationToken);
+
+            // Kick off work to search the online code index system in parallel
+            var codeIndexReferencesTask = FindCodeIndexReferencesAsync(
+                codeIndexProvider,
+                symbol,
+                project.Solution,
+                progressAdapter,
+                options,
+                cancellationToken);
+
+            await Task.WhenAll(normalFindReferencesTask, codeIndexReferencesTask).ConfigureAwait(false);
+        }
+
+        private async Task FindCodeIndexReferencesAsync(
+            ICodeIndexProvider? codeIndexProvider,
+            ISymbol symbol, Solution solution,
+            FindReferencesProgressAdapter progressAdapter,
+            FindReferencesSearchOptions options,
+            CancellationToken cancellationToken)
+        {
+            if (codeIndexProvider == null)
+                return;
+
+            var moniker = SymbolMoniker.TryCreate(symbol);
+            if (moniker == null)
+                return;
+
+            var monikers = SpecializedCollections.SingletonEnumerable(moniker);
+            var currentPage = 0;
+            while (true)
+            {
+                var results = await codeIndexProvider.FindReferencesByMonikerAsync(
+                    monikers, includeDecleration: true, pageIndex: currentPage, cancellationToken: cancellationToken).ConfigureAwait(false);
+                if (results == null || results.Count == 0)
+                    break;
+
+                currentPage++;
+                await ProcessCodeIndexResultsAsync(
+                    codeIndexProvider, results, cancellationToken).ConfigureAwait(false);
+            }
         }
 
         private async Task<bool> TryFindLiteralReferencesAsync(
@@ -170,8 +214,8 @@ protected AbstractFindUsagesService(IThreadingContext threadingContext)
             var cancellationToken = context.CancellationToken;
             cancellationToken.ThrowIfCancellationRequested();
 
-            var syntaxTree = await document.GetSyntaxTreeAsync(cancellationToken).ConfigureAwait(false);
-            var syntaxFacts = document.GetLanguageService<ISyntaxFactsService>();
+            var syntaxTree = await document.GetRequiredSyntaxTreeAsync(cancellationToken).ConfigureAwait(false);
+            var syntaxFacts = document.GetRequiredLanguageService<ISyntaxFactsService>();
 
             // Currently we only support FAR for numbers, strings and characters.  We don't
             // bother with true/false/null as those are likely to have way too many results
@@ -192,20 +236,19 @@ protected AbstractFindUsagesService(IThreadingContext threadingContext)
             // for numeric values, and a decimal won't fit within that.
             var tokenValue = token.Value;
             if (tokenValue == null || tokenValue is decimal)
-            {
                 return false;
-            }
 
-            var semanticModel = await document.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);
+            if (token.Parent is null)
+                return false;
+
+            var semanticModel = await document.GetRequiredSemanticModelAsync(cancellationToken).ConfigureAwait(false);
             var symbol = semanticModel.GetSymbolInfo(token.Parent).Symbol ?? semanticModel.GetDeclaredSymbol(token.Parent);
 
             // Numeric labels are available in VB.  In that case we want the normal FAR engine to
             // do the searching.  For these literals we want to find symbolic results and not 
             // numeric matches.
             if (symbol is ILabelSymbol)
-            {
                 return false;
-            }
 
             // Use the literal to make the title.  Trim literal if it's too long.
             var title = syntaxFacts.ConvertToSingleLine(token.Parent).ToString();