diff --git a/src/Microsoft.AspNet.Razor/GeneratorResults.cs b/src/Microsoft.AspNet.Razor/GeneratorResults.cs
index 2ea36e30bf..ec02a3f935 100644
--- a/src/Microsoft.AspNet.Razor/GeneratorResults.cs
+++ b/src/Microsoft.AspNet.Razor/GeneratorResults.cs
@@ -4,43 +4,84 @@
 using System.Collections.Generic;
 using Microsoft.AspNet.Razor.Generator.Compiler;
 using Microsoft.AspNet.Razor.Parser.SyntaxTree;
+using Microsoft.AspNet.Razor.TagHelpers;
 
 namespace Microsoft.AspNet.Razor
 {
+    /// <summary>
+    /// The results of parsing and generating code for a Razor document.
+    /// </summary>
     public class GeneratorResults : ParserResults
     {
-        public GeneratorResults(ParserResults parserResults, CodeBuilderResult codeBuilderResult, CodeTree codeTree)
+        /// <summary>
+        /// Instantiates a new <see cref="GeneratorResults"/> instance.
+        /// </summary>
+        /// <param name="parserResults">The results of parsing a document.</param>
+        /// <param name="codeBuilderResult">The results of generating code for the document.</param>
+        /// <param name="codeTree">A <see cref="CodeTree"/> for the document.</param>
+        public GeneratorResults([NotNull] ParserResults parserResults,
+                                [NotNull] CodeBuilderResult codeBuilderResult,
+                                [NotNull] CodeTree codeTree)
             : this(parserResults.Document,
+                   parserResults.TagHelperDescriptors,
                    parserResults.ParserErrors,
                    codeBuilderResult,
                    codeTree)
         {
         }
 
-        public GeneratorResults(Block document,
-                                IList<RazorError> parserErrors,
-                                CodeBuilderResult codeBuilderResult,
-                                CodeTree codeTree)
-            : this(parserErrors.Count == 0, document, parserErrors, codeBuilderResult, codeTree)
+        /// <summary>
+        /// Instantiates a new <see cref="GeneratorResults"/> instance.
+        /// </summary>
+        /// <param name="document">The <see cref="Block"/> for the syntax tree.</param>
+        /// <param name="tagHelperDescriptors"><see cref="TagHelperDescriptor"/>s for the document.</param>
+        /// <param name="parserErrors"><see cref="RazorError"/>s encountered when parsing the document.</param>
+        /// <param name="codeBuilderResult">The results of generating code for the document.</param>
+        /// <param name="codeTree">A <see cref="CodeTree"/> for the document.</param>
+        public GeneratorResults([NotNull] Block document,
+                                [NotNull] IEnumerable<TagHelperDescriptor> tagHelperDescriptors,
+                                [NotNull] IList<RazorError> parserErrors,
+                                [NotNull] CodeBuilderResult codeBuilderResult,
+                                [NotNull] CodeTree codeTree)
+            : this(parserErrors.Count == 0, document, tagHelperDescriptors, parserErrors, codeBuilderResult, codeTree)
         {
         }
 
+        /// <summary>
+        /// Instantiates a new <see cref="GeneratorResults"/> instance.
+        /// </summary>
+        /// <param name="success"><c>true</c> if parsing was successful, <c>false</c> otherwise.</param>
+        /// <param name="document">The <see cref="Block"/> for the syntax tree.</param>
+        /// <param name="tagHelperDescriptors"><see cref="TagHelperDescriptor"/>s for the document.</param>
+        /// <param name="parserErrors"><see cref="RazorError"/>s encountered when parsing the document.</param>
+        /// <param name="codeBuilderResult">The results of generating code for the document.</param>
+        /// <param name="codeTree">A <see cref="CodeTree"/> for the document.</param>
         protected GeneratorResults(bool success,
-                                   Block document,
-                                   IList<RazorError> parserErrors,
-                                   CodeBuilderResult codeBuilderResult,
-                                   CodeTree codeTree)
-            : base(success, document, parserErrors)
+                                   [NotNull] Block document,
+                                   [NotNull] IEnumerable<TagHelperDescriptor> tagHelperDescriptors,
+                                   [NotNull] IList<RazorError> parserErrors,
+                                   [NotNull] CodeBuilderResult codeBuilderResult,
+                                   [NotNull] CodeTree codeTree)
+            : base(success, document, tagHelperDescriptors, parserErrors)
         {
             GeneratedCode = codeBuilderResult.Code;
             DesignTimeLineMappings = codeBuilderResult.DesignTimeLineMappings;
             CodeTree = codeTree;
         }
 
-        public string GeneratedCode { get; private set; }
+        /// <summary>
+        /// The generated code for the document.
+        /// </summary>
+        public string GeneratedCode { get; }
 
-        public IList<LineMapping> DesignTimeLineMappings { get; private set; }
+        /// <summary>
+        /// <see cref="LineMapping"/>s used to project code from a file during design time.
+        /// </summary>
+        public IList<LineMapping> DesignTimeLineMappings { get; }
 
-        public CodeTree CodeTree { get; private set; }
+        /// <summary>
+        /// A <see cref="Generator.Compiler.CodeTree"/> for the document.
+        /// </summary>
+        public CodeTree CodeTree { get; }
     }
 }
diff --git a/src/Microsoft.AspNet.Razor/Parser/ParserContext.cs b/src/Microsoft.AspNet.Razor/Parser/ParserContext.cs
index cd5d0ce808..fa0a9bbf4b 100644
--- a/src/Microsoft.AspNet.Razor/Parser/ParserContext.cs
+++ b/src/Microsoft.AspNet.Razor/Parser/ParserContext.cs
@@ -9,6 +9,7 @@ using System.Globalization;
 using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.AspNet.Razor.Parser.SyntaxTree;
+using Microsoft.AspNet.Razor.TagHelpers;
 using Microsoft.AspNet.Razor.Text;
 using Microsoft.AspNet.Razor.Utils;
 
@@ -225,7 +226,11 @@ namespace Microsoft.AspNet.Razor.Parser
                 throw new InvalidOperationException(RazorResources.ParserContext_CannotCompleteTree_OutstandingBlocks);
             }
 
-            return new ParserResults(_blockStack.Pop().Build(), _errorSink.Errors.ToList());
+            return new ParserResults(_blockStack.Pop().Build(),
+                                     // TagHelperDescriptors are not found by default. The RazorParser is responsible 
+                                     // for identifying TagHelperDescriptors and rebuilding ParserResults.
+                                     tagHelperDescriptors: Enumerable.Empty<TagHelperDescriptor>(),
+                                     parserErrors: _errorSink.Errors.ToList());
         }
 
         [Conditional("DEBUG")]
diff --git a/src/Microsoft.AspNet.Razor/Parser/RazorParser.cs b/src/Microsoft.AspNet.Razor/Parser/RazorParser.cs
index 4d2a21d1ec..01a04ed8e3 100644
--- a/src/Microsoft.AspNet.Razor/Parser/RazorParser.cs
+++ b/src/Microsoft.AspNet.Razor/Parser/RazorParser.cs
@@ -170,9 +170,11 @@ namespace Microsoft.AspNet.Razor.Parser
                 rewriter.Rewrite(rewritingContext);
             }
 
+            var descriptors = Enumerable.Empty<TagHelperDescriptor>();
+
             if (TagHelperDescriptorResolver != null)
             {
-                var descriptors = GetTagHelperDescriptors(rewritingContext.SyntaxTree, rewritingContext.ErrorSink);
+                descriptors = GetTagHelperDescriptors(rewritingContext.SyntaxTree, rewritingContext.ErrorSink);
                 var tagHelperProvider = new TagHelperDescriptorProvider(descriptors);
 
                 var tagHelperParseTreeRewriter = new TagHelperParseTreeRewriter(tagHelperProvider);
@@ -195,7 +197,7 @@ namespace Microsoft.AspNet.Razor.Parser
             }
 
             // Return the new result
-            return new ParserResults(syntaxTree, errorSink.Errors.ToList());
+            return new ParserResults(syntaxTree, descriptors, errorSink.Errors.ToList());
         }
 
         /// <summary>
diff --git a/src/Microsoft.AspNet.Razor/ParserResults.cs b/src/Microsoft.AspNet.Razor/ParserResults.cs
index 19a8f0230e..97df423630 100644
--- a/src/Microsoft.AspNet.Razor/ParserResults.cs
+++ b/src/Microsoft.AspNet.Razor/ParserResults.cs
@@ -3,6 +3,7 @@
 
 using System.Collections.Generic;
 using Microsoft.AspNet.Razor.Parser.SyntaxTree;
+using Microsoft.AspNet.Razor.TagHelpers;
 
 namespace Microsoft.AspNet.Razor
 {
@@ -11,15 +12,38 @@ namespace Microsoft.AspNet.Razor
     /// </summary>
     public class ParserResults
     {
-        public ParserResults(Block document, IList<RazorError> parserErrors)
-            : this(parserErrors == null || parserErrors.Count == 0, document, parserErrors)
+        /// <summary>
+        /// Instantiates a new <see cref="ParserResults"/> instance.
+        /// </summary>
+        /// <param name="document">The Razor syntax tree.</param>
+        /// <param name="tagHelperDescriptors"><see cref="TagHelperDescriptor"/>s that apply to the current Razor 
+        /// document.</param>
+        /// <param name="parserErrors"><see cref="RazorError"/>s encountered when parsing the current Razor
+        /// document.</param>
+        public ParserResults([NotNull] Block document,
+                             [NotNull] IEnumerable<TagHelperDescriptor> tagHelperDescriptors,
+                             [NotNull] IList<RazorError> parserErrors)
+            : this(parserErrors == null || parserErrors.Count == 0, document, tagHelperDescriptors, parserErrors)
         {
         }
 
-        protected ParserResults(bool success, Block document, IList<RazorError> errors)
+        /// <summary>
+        /// Instantiates a new <see cref="ParserResults"/> instance.
+        /// </summary>
+        /// <param name="success"><c>true</c> if parsing was successful, <c>false</c> otherwise.</param>
+        /// <param name="document">The Razor syntax tree.</param>
+        /// <param name="tagHelperDescriptors"><see cref="TagHelperDescriptor"/>s that apply to the current Razor 
+        /// document.</param>
+        /// <param name="errors"><see cref="RazorError"/>s encountered when parsing the current Razor
+        /// document.</param>
+        protected ParserResults(bool success,
+                                [NotNull] Block document,
+                                [NotNull] IEnumerable<TagHelperDescriptor> tagHelperDescriptors,
+                                [NotNull] IList<RazorError> errors)
         {
             Success = success;
             Document = document;
+            TagHelperDescriptors = tagHelperDescriptors;
             ParserErrors = errors ?? new List<RazorError>();
         }
 
@@ -37,5 +61,10 @@ namespace Microsoft.AspNet.Razor
         /// The list of errors which occurred during parsing.
         /// </summary>
         public IList<RazorError> ParserErrors { get; private set; }
+
+        /// <summary>
+        /// The <see cref="TagHelperDescriptor"/>s found for the current Razor document.
+        /// </summary>
+        public IEnumerable<TagHelperDescriptor> TagHelperDescriptors { get; private set; }
     }
 }
diff --git a/test/Microsoft.AspNet.Razor.Test/Generator/CSharpTagHelperRenderingTest.cs b/test/Microsoft.AspNet.Razor.Test/Generator/CSharpTagHelperRenderingTest.cs
index 85dee97c23..ef5c9e36de 100644
--- a/test/Microsoft.AspNet.Razor.Test/Generator/CSharpTagHelperRenderingTest.cs
+++ b/test/Microsoft.AspNet.Razor.Test/Generator/CSharpTagHelperRenderingTest.cs
@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System.Collections.Generic;
+using System.Linq;
 #if ASPNETCORE50
 using System.Reflection;
 #endif
@@ -63,6 +64,98 @@ namespace Microsoft.AspNet.Razor.Test.Generator
             }
         }
 
+        public static TheoryData TagHelperDescriptorFlowTestData
+        {
+            get
+            {
+                return new TheoryData<string, // Test name
+                                      string, // Baseline name
+                                      IEnumerable<TagHelperDescriptor>, // TagHelperDescriptors provided
+                                      IEnumerable<TagHelperDescriptor>, // Expected TagHelperDescriptors
+                                      bool> // Design time mode.
+                {
+                    {
+                        "SingleTagHelper",
+                        "SingleTagHelper",
+                        PAndInputTagHelperDescriptors,
+                        PAndInputTagHelperDescriptors,
+                        false
+                    },
+                    {
+                        "SingleTagHelper",
+                        "SingleTagHelper.DesignTime",
+                        PAndInputTagHelperDescriptors,
+                        PAndInputTagHelperDescriptors,
+                        true
+                    },
+                    {
+                        "BasicTagHelpers",
+                        "BasicTagHelpers",
+                        PAndInputTagHelperDescriptors,
+                        PAndInputTagHelperDescriptors,
+                        false
+                    },
+                    {
+                        "BasicTagHelpers",
+                        "BasicTagHelpers.DesignTime",
+                        PAndInputTagHelperDescriptors,
+                        PAndInputTagHelperDescriptors,
+                        true
+                    },
+                    {
+                        "BasicTagHelpers.RemoveTagHelper",
+                        "BasicTagHelpers.RemoveTagHelper",
+                        PAndInputTagHelperDescriptors,
+                        Enumerable.Empty<TagHelperDescriptor>(),
+                        false
+                    },
+                    {
+                        "ContentBehaviorTagHelpers",
+                        "ContentBehaviorTagHelpers",
+                        ContentBehaviorTagHelperDescriptors,
+                        ContentBehaviorTagHelperDescriptors,
+                        false
+                    },
+                    {
+                        "ComplexTagHelpers",
+                        "ComplexTagHelpers",
+                        PAndInputTagHelperDescriptors,
+                        PAndInputTagHelperDescriptors,
+                        false
+                    },
+                    {
+                        "ComplexTagHelpers",
+                        "ComplexTagHelpers.DesignTime",
+                        PAndInputTagHelperDescriptors,
+                        PAndInputTagHelperDescriptors,
+                        true
+                    }
+                };
+            }
+        }
+
+        [Theory]
+        [MemberData(nameof(TagHelperDescriptorFlowTestData))]
+        public void TagHelpers_RenderingOutputFlowsFoundTagHelperDescriptors(
+            string testName,
+            string baselineName,
+            IEnumerable<TagHelperDescriptor> tagHelperDescriptors,
+            IEnumerable<TagHelperDescriptor> expectedTagHelperDescriptors,
+            bool designTimeMode)
+        {
+            RunTagHelperTest(
+                testName, 
+                baseLineName: baselineName,
+                tagHelperDescriptors: tagHelperDescriptors,
+                onResults: (results) =>
+                {
+                    Assert.Equal(expectedTagHelperDescriptors,
+                                 results.TagHelperDescriptors,
+                                 TagHelperDescriptorComparer.Default);
+                },
+                designTimeMode: designTimeMode);
+        }
+
         public static TheoryData DesignTimeTagHelperTestData
         {
             get
diff --git a/test/Microsoft.AspNet.Razor.Test/Generator/TagHelperTestBase.cs b/test/Microsoft.AspNet.Razor.Test/Generator/TagHelperTestBase.cs
index 37cc1214f3..31ac2e2dcd 100644
--- a/test/Microsoft.AspNet.Razor.Test/Generator/TagHelperTestBase.cs
+++ b/test/Microsoft.AspNet.Razor.Test/Generator/TagHelperTestBase.cs
@@ -3,10 +3,12 @@
 
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Linq;
 using Microsoft.AspNet.Razor.Generator.Compiler;
 using Microsoft.AspNet.Razor.Parser;
 using Microsoft.AspNet.Razor.TagHelpers;
+using Xunit;
 
 namespace Microsoft.AspNet.Razor.Test.Generator
 {
@@ -17,7 +19,8 @@ namespace Microsoft.AspNet.Razor.Test.Generator
                                         bool designTimeMode = false,
                                         IEnumerable<TagHelperDescriptor> tagHelperDescriptors = null,
                                         Func<RazorEngineHost, RazorEngineHost> hostConfig = null,
-                                        IList<LineMapping> expectedDesignTimePragmas = null)
+                                        IList<LineMapping> expectedDesignTimePragmas = null,
+                                        Action<GeneratorResults> onResults = null)
         {
             RunTest(name: testName,
                     baselineName: baseLineName,
@@ -27,6 +30,7 @@ namespace Microsoft.AspNet.Razor.Test.Generator
                     {
                         return new TagHelperTemplateEngine(engine, tagHelperDescriptors);
                     },
+                    onResults: onResults,
                     hostConfig: hostConfig,
                     expectedDesignTimePragmas: expectedDesignTimePragmas);
         }
diff --git a/test/Microsoft.AspNet.Razor.Test/Parser/ParserVisitorExtensionsTest.cs b/test/Microsoft.AspNet.Razor.Test/Parser/ParserVisitorExtensionsTest.cs
index 31535af4a9..264c8be456 100644
--- a/test/Microsoft.AspNet.Razor.Test/Parser/ParserVisitorExtensionsTest.cs
+++ b/test/Microsoft.AspNet.Razor.Test/Parser/ParserVisitorExtensionsTest.cs
@@ -4,8 +4,10 @@
 #if !ASPNETCORE50
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using Microsoft.AspNet.Razor.Parser;
 using Microsoft.AspNet.Razor.Parser.SyntaxTree;
+using Microsoft.AspNet.Razor.TagHelpers;
 using Moq;
 using Xunit;
 
@@ -17,7 +19,9 @@ namespace Microsoft.AspNet.Razor.Test.Parser
         public void VisitThrowsOnNullVisitor()
         {
             ParserVisitor target = null;
-            var results = new ParserResults(new BlockBuilder() { Type = BlockType.Comment }.Build(), new List<RazorError>());
+            var results = new ParserResults(new BlockBuilder() { Type = BlockType.Comment }.Build(),
+                                            Enumerable.Empty<TagHelperDescriptor>(),
+                                            parserErrors: new List<RazorError>());
 
             Assert.Throws<ArgumentNullException>("self", () => target.Visit(results));
         }
@@ -35,7 +39,9 @@ namespace Microsoft.AspNet.Razor.Test.Parser
             // Arrange
             Mock<ParserVisitor> targetMock = new Mock<ParserVisitor>();
             var root = new BlockBuilder() { Type = BlockType.Comment }.Build();
-            var results = new ParserResults(root, new List<RazorError>());
+            var results = new ParserResults(root,
+                                            Enumerable.Empty<TagHelperDescriptor>(),
+                                            parserErrors: new List<RazorError>());
 
             // Act
             targetMock.Object.Visit(results);
@@ -54,7 +60,7 @@ namespace Microsoft.AspNet.Razor.Test.Parser
                 new RazorError("Foo", 1, 0, 1),
                 new RazorError("Bar", 2, 0, 2)
             };
-            var results = new ParserResults(root, errors);
+            var results = new ParserResults(root, Enumerable.Empty<TagHelperDescriptor>(), errors);
 
             // Act
             targetMock.Object.Visit(results);
@@ -74,7 +80,7 @@ namespace Microsoft.AspNet.Razor.Test.Parser
                 new RazorError("Foo", 1, 0, 1),
                 new RazorError("Bar", 2, 0, 2)
             };
-            var results = new ParserResults(root, errors);
+            var results = new ParserResults(root, Enumerable.Empty<TagHelperDescriptor>(), errors);
 
             // Act
             targetMock.Object.Visit(results);