diff --git a/src/compiler/builder.ts b/src/compiler/builder.ts
index faf51568241f5..f72f30b226cab 100644
--- a/src/compiler/builder.ts
+++ b/src/compiler/builder.ts
@@ -792,7 +792,7 @@ namespace ts {
                             state,
                             // When whole program is affected, do emit only once (eg when --out or --outFile is specified)
                             // Otherwise just affected file
-                            affected.emitBuildInfo(writeFile || host.writeFile, cancellationToken),
+                            affected.emitBuildInfo(writeFile || maybeBind(host, host.writeFile), cancellationToken),
                             affected,
                             /*isPendingEmitFile*/ false,
                             /*isBuildInfoEmit*/ true
@@ -820,7 +820,7 @@ namespace ts {
                 state,
                 // When whole program is affected, do emit only once (eg when --out or --outFile is specified)
                 // Otherwise just affected file
-                Debug.assertDefined(state.program).emit(affected === state.program ? undefined : affected as SourceFile, writeFile || host.writeFile, cancellationToken, emitOnlyDtsFiles, customTransformers),
+                Debug.assertDefined(state.program).emit(affected === state.program ? undefined : affected as SourceFile, writeFile || maybeBind(host, host.writeFile), cancellationToken, emitOnlyDtsFiles, customTransformers),
                 affected,
                 isPendingEmitFile
             );
@@ -862,7 +862,7 @@ namespace ts {
                     };
                 }
             }
-            return Debug.assertDefined(state.program).emit(targetSourceFile, writeFile || host.writeFile, cancellationToken, emitOnlyDtsFiles, customTransformers);
+            return Debug.assertDefined(state.program).emit(targetSourceFile, writeFile || maybeBind(host, host.writeFile), cancellationToken, emitOnlyDtsFiles, customTransformers);
         }
 
         /**
diff --git a/src/compiler/commandLineParser.ts b/src/compiler/commandLineParser.ts
index 3c4b0577fb664..12a20e0df42e1 100644
--- a/src/compiler/commandLineParser.ts
+++ b/src/compiler/commandLineParser.ts
@@ -136,6 +136,13 @@ namespace ts {
             category: Diagnostics.Advanced_Options,
             description: Diagnostics.Show_verbose_diagnostic_information
         },
+        {
+            name: "incremental",
+            shortName: "i",
+            type: "boolean",
+            category: Diagnostics.Basic_Options,
+            description: Diagnostics.Enable_incremental_compilation,
+        },
     ];
 
     /* @internal */
@@ -331,19 +338,11 @@ namespace ts {
             category: Diagnostics.Basic_Options,
             description: Diagnostics.Enable_project_compilation,
         },
-        {
-            name: "incremental",
-            type: "boolean",
-            isTSConfigOnly: true,
-            category: Diagnostics.Basic_Options,
-            description: Diagnostics.Enable_incremental_compilation,
-        },
         {
             name: "tsBuildInfoFile",
             type: "string",
             isFilePath: true,
             paramType: Diagnostics.FILE,
-            isTSConfigOnly: true,
             category: Diagnostics.Basic_Options,
             description: Diagnostics.Specify_file_to_store_incremental_compilation_information,
         },
diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json
index 9ae3e1ca77eae..6cb498df8279e 100644
--- a/src/compiler/diagnosticMessages.json
+++ b/src/compiler/diagnosticMessages.json
@@ -3072,6 +3072,10 @@
         "category": "Error",
         "code": 5073
     },
+    "Option '--incremental' can only be specified using tsconfig, emitting to single file or when option `--tsBuildInfoFile` is specified.": {
+        "category": "Error",
+        "code": 5074
+    },
 
     "Generates a sourcemap for each corresponding '.d.ts' file.": {
         "category": "Message",
diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
index be867db68fb77..8f91e3d25c163 100644
--- a/src/compiler/emitter.ts
+++ b/src/compiler/emitter.ts
@@ -54,7 +54,7 @@ namespace ts {
     /*@internal*/
     export function getOutputPathForBuildInfo(options: CompilerOptions) {
         const configFile = options.configFilePath;
-        if (!configFile || !isIncrementalCompilation(options)) return undefined;
+        if (!isIncrementalCompilation(options)) return undefined;
         if (options.tsBuildInfoFile) return options.tsBuildInfoFile;
         const outPath = options.outFile || options.out;
         let buildInfoExtensionLess: string;
@@ -62,6 +62,7 @@ namespace ts {
             buildInfoExtensionLess = removeFileExtension(outPath);
         }
         else {
+            if (!configFile) return undefined;
             const configFileExtensionLess = removeFileExtension(configFile);
             buildInfoExtensionLess = options.outDir ?
                 options.rootDir ?
diff --git a/src/compiler/program.ts b/src/compiler/program.ts
index b188e708a623f..6418f55968ba3 100644
--- a/src/compiler/program.ts
+++ b/src/compiler/program.ts
@@ -193,7 +193,8 @@ namespace ts {
             getDirectories: (path: string) => system.getDirectories(path),
             realpath,
             readDirectory: (path, extensions, include, exclude, depth) => system.readDirectory(path, extensions, include, exclude, depth),
-            createDirectory: d => system.createDirectory(d)
+            createDirectory: d => system.createDirectory(d),
+            createHash: maybeBind(system, system.createHash)
         };
         return compilerHost;
     }
@@ -315,7 +316,10 @@ namespace ts {
         };
     }
 
-    export function getPreEmitDiagnostics(program: Program, sourceFile?: SourceFile, cancellationToken?: CancellationToken): ReadonlyArray<Diagnostic> {
+    // tslint:disable unified-signatures
+    export function getPreEmitDiagnostics(program: Program, sourceFile?: SourceFile, cancellationToken?: CancellationToken): ReadonlyArray<Diagnostic>;
+    /*@internal*/ export function getPreEmitDiagnostics(program: BuilderProgram, sourceFile?: SourceFile, cancellationToken?: CancellationToken): ReadonlyArray<Diagnostic>;
+    export function getPreEmitDiagnostics(program: Program | BuilderProgram, sourceFile?: SourceFile, cancellationToken?: CancellationToken): ReadonlyArray<Diagnostic> {
         const diagnostics = [
             ...program.getConfigFileParsingDiagnostics(),
             ...program.getOptionsDiagnostics(cancellationToken),
@@ -330,6 +334,7 @@ namespace ts {
 
         return sortAndDeduplicateDiagnostics(diagnostics);
     }
+    // tslint:enable unified-signatures
 
     export interface FormatDiagnosticsHost {
         getCurrentDirectory(): string;
@@ -2730,6 +2735,9 @@ namespace ts {
                     createDiagnosticForOptionName(Diagnostics.Option_0_cannot_be_specified_without_specifying_option_1_or_option_2, "tsBuildInfoFile", "incremental", "composite");
                 }
             }
+            else if (options.incremental && !options.outFile && !options.out && !options.configFilePath) {
+                programDiagnostics.add(createCompilerDiagnostic(Diagnostics.Option_incremental_can_only_be_specified_using_tsconfig_emitting_to_single_file_or_when_option_tsBuildInfoFile_is_specified));
+            }
 
             verifyProjectReferences();
 
diff --git a/src/compiler/tsbuild.ts b/src/compiler/tsbuild.ts
index cc79c02f1d69e..16e6e42272ea9 100644
--- a/src/compiler/tsbuild.ts
+++ b/src/compiler/tsbuild.ts
@@ -30,6 +30,7 @@ namespace ts {
         listEmittedFiles?: boolean;
         listFiles?: boolean;
         pretty?: boolean;
+        incremental?: boolean;
 
         traceResolution?: boolean;
         /* @internal */ diagnostics?: boolean;
@@ -363,7 +364,7 @@ namespace ts {
     function getCompilerOptionsOfBuildOptions(buildOptions: BuildOptions): CompilerOptions {
         const result = {} as CompilerOptions;
         commonOptionsWithBuild.forEach(option => {
-            result[option.name] = buildOptions[option.name];
+            if (hasProperty(buildOptions, option.name)) result[option.name] = buildOptions[option.name];
         });
         return result;
     }
diff --git a/src/services/codefixes/fixAddMissingMember.ts b/src/services/codefixes/fixAddMissingMember.ts
index 98ddee61f8e8d..843d22554ed87 100644
--- a/src/services/codefixes/fixAddMissingMember.ts
+++ b/src/services/codefixes/fixAddMissingMember.ts
@@ -12,7 +12,7 @@ namespace ts.codefix {
     registerCodeFix({
         errorCodes,
         getCodeActions(context) {
-            const info = getInfo(context.sourceFile, context.span.start, context.program.getTypeChecker());
+            const info = getInfo(context.sourceFile, context.span.start, context.program.getTypeChecker(), context.program);
             if (!info) return undefined;
 
             if (info.kind === InfoKind.Enum) {
@@ -37,7 +37,7 @@ namespace ts.codefix {
 
             return createCombinedCodeActions(textChanges.ChangeTracker.with(context, changes => {
                 eachDiagnostic(context, errorCodes, diag => {
-                    const info = getInfo(diag.file, diag.start, checker);
+                    const info = getInfo(diag.file, diag.start, checker, context.program);
                     if (!info || !addToSeen(seen, getNodeId(info.parentDeclaration) + "#" + info.token.text)) {
                         return;
                     }
@@ -113,7 +113,7 @@ namespace ts.codefix {
     }
     type Info = EnumInfo | ClassOrInterfaceInfo;
 
-    function getInfo(tokenSourceFile: SourceFile, tokenPos: number, checker: TypeChecker): Info | undefined {
+    function getInfo(tokenSourceFile: SourceFile, tokenPos: number, checker: TypeChecker, program: Program): Info | undefined {
         // The identifier of the missing property. eg:
         // this.missing = 1;
         //      ^^^^^^^
@@ -131,7 +131,7 @@ namespace ts.codefix {
 
         // Prefer to change the class instead of the interface if they are merged
         const classOrInterface = find(symbol.declarations, isClassLike) || find(symbol.declarations, isInterfaceDeclaration);
-        if (classOrInterface) {
+        if (classOrInterface && !program.isSourceFileFromExternalLibrary(classOrInterface.getSourceFile())) {
             const makeStatic = ((leftExpressionType as TypeReference).target || leftExpressionType) !== checker.getDeclaredTypeOfSymbol(symbol);
             const declSourceFile = classOrInterface.getSourceFile();
             const inJs = isSourceFileJS(declSourceFile);
@@ -139,7 +139,7 @@ namespace ts.codefix {
             return { kind: InfoKind.ClassOrInterface, token, parentDeclaration: classOrInterface, makeStatic, declSourceFile, inJs, call };
         }
         const enumDeclaration = find(symbol.declarations, isEnumDeclaration);
-        if (enumDeclaration) {
+        if (enumDeclaration && !program.isSourceFileFromExternalLibrary(enumDeclaration.getSourceFile())) {
             return { kind: InfoKind.Enum, token, parentDeclaration: enumDeclaration };
         }
         return undefined;
diff --git a/src/testRunner/unittests/config/commandLineParsing.ts b/src/testRunner/unittests/config/commandLineParsing.ts
index 26a49df3dbb15..ccb2378c644a8 100644
--- a/src/testRunner/unittests/config/commandLineParsing.ts
+++ b/src/testRunner/unittests/config/commandLineParsing.ts
@@ -365,6 +365,26 @@ namespace ts {
                     }
                 });
         });
+
+        it("parse --incremental", () => {
+            // --lib es6 0.ts
+            assertParseResult(["--incremental", "0.ts"],
+                {
+                    errors: [],
+                    fileNames: ["0.ts"],
+                    options: { incremental: true }
+                });
+        });
+
+        it("parse --tsBuildInfoFile", () => {
+            // --lib es6 0.ts
+            assertParseResult(["--tsBuildInfoFile", "build.tsbuildinfo", "0.ts"],
+                {
+                    errors: [],
+                    fileNames: ["0.ts"],
+                    options: { tsBuildInfoFile: "build.tsbuildinfo" }
+                });
+        });
     });
 
     describe("unittests:: config:: commandLineParsing:: parseBuildOptions", () => {
@@ -456,6 +476,33 @@ namespace ts {
                 });
         });
 
+        it("parse build with --incremental", () => {
+            // --lib es6 0.ts
+            assertParseResult(["--incremental", "tests"],
+                {
+                    errors: [],
+                    projects: ["tests"],
+                    buildOptions: { incremental: true }
+                });
+        });
+
+        it("parse build with --tsBuildInfoFile", () => {
+            // --lib es6 0.ts
+            assertParseResult(["--tsBuildInfoFile", "build.tsbuildinfo", "tests"],
+                {
+                    errors: [{
+                        messageText: "Unknown build option '--tsBuildInfoFile'.",
+                        category: Diagnostics.Unknown_build_option_0.category,
+                        code: Diagnostics.Unknown_build_option_0.code,
+                        file: undefined,
+                        start: undefined,
+                        length: undefined
+                    }],
+                    projects: ["build.tsbuildinfo", "tests"],
+                    buildOptions: { }
+                });
+        });
+
         describe("Combining options that make no sense together", () => {
             function verifyInvalidCombination(flag1: keyof BuildOptions, flag2: keyof BuildOptions) {
                 it(`--${flag1} and --${flag2} together is invalid`, () => {
diff --git a/src/testRunner/unittests/tsbuild/outFile.ts b/src/testRunner/unittests/tsbuild/outFile.ts
index 5328806565835..48beeef4f61da 100644
--- a/src/testRunner/unittests/tsbuild/outFile.ts
+++ b/src/testRunner/unittests/tsbuild/outFile.ts
@@ -197,8 +197,8 @@ namespace ts {
             dtsUnchangedExpectedReadFilesDependOrdered = undefined!;
         });
 
-        function createSolutionBuilder(host: fakes.SolutionBuilderHost) {
-            return ts.createSolutionBuilder(host, ["/src/third"], { dry: false, force: false, verbose: true });
+        function createSolutionBuilder(host: fakes.SolutionBuilderHost, baseOptions?: BuildOptions) {
+            return ts.createSolutionBuilder(host, ["/src/third"], { dry: false, force: false, verbose: true, ...(baseOptions || {}) });
         }
 
         function getInitialExpectedReadFiles(additionalSourceFiles?: ReadonlyArray<string>) {
@@ -446,6 +446,49 @@ namespace ts {
             );
         });
 
+        it("rebuilds completely when command line incremental flag changes between non dts changes", () => {
+            const fs = outFileFs.shadow();
+            // Make non composite third project
+            replaceText(fs, sources[project.third][source.config], `"composite": true,`, "");
+
+            // Build with command line incremental
+            const host = new fakes.SolutionBuilderHost(fs);
+            const builder = createSolutionBuilder(host, { incremental: true });
+            builder.buildAllProjects();
+            host.assertDiagnosticMessages(...initialExpectedDiagnostics);
+            host.clearDiagnostics();
+            tick();
+
+            // Make non incremental build with change in file that doesnt affect dts
+            appendText(fs, relSources[project.first][source.ts][part.one], "console.log(s);");
+            builder.resetBuildContext({ verbose: true });
+            builder.buildAllProjects();
+            host.assertDiagnosticMessages(getExpectedDiagnosticForProjectsInBuild(relSources[project.first][source.config], relSources[project.second][source.config], relSources[project.third][source.config]),
+                [Diagnostics.Project_0_is_out_of_date_because_oldest_output_1_is_older_than_newest_input_2, relSources[project.first][source.config], relOutputFiles[project.first][ext.js], relSources[project.first][source.ts][part.one]],
+                [Diagnostics.Building_project_0, sources[project.first][source.config]],
+                [Diagnostics.Project_0_is_up_to_date_because_newest_input_1_is_older_than_oldest_output_2, relSources[project.second][source.config], relSources[project.second][source.ts][part.one], relOutputFiles[project.second][ext.js]],
+                [Diagnostics.Project_0_is_out_of_date_because_output_of_its_dependency_1_has_changed, relSources[project.third][source.config], "src/first"],
+                [Diagnostics.Building_project_0, sources[project.third][source.config]]
+            );
+            host.clearDiagnostics();
+            tick();
+
+            // Make incremental build with change in file that doesnt affect dts
+            appendText(fs, relSources[project.first][source.ts][part.one], "console.log(s);");
+            builder.resetBuildContext({ verbose: true, incremental: true });
+            builder.buildAllProjects();
+            // Builds completely because tsbuildinfo is old.
+            host.assertDiagnosticMessages(
+                getExpectedDiagnosticForProjectsInBuild(relSources[project.first][source.config], relSources[project.second][source.config], relSources[project.third][source.config]),
+                [Diagnostics.Project_0_is_out_of_date_because_oldest_output_1_is_older_than_newest_input_2, relSources[project.first][source.config], relOutputFiles[project.first][ext.js], relSources[project.first][source.ts][part.one]],
+                [Diagnostics.Building_project_0, sources[project.first][source.config]],
+                [Diagnostics.Project_0_is_up_to_date_because_newest_input_1_is_older_than_oldest_output_2, relSources[project.second][source.config], relSources[project.second][source.ts][part.one], relOutputFiles[project.second][ext.js]],
+                [Diagnostics.Project_0_is_out_of_date_because_oldest_output_1_is_older_than_newest_input_2, relSources[project.third][source.config], relOutputFiles[project.third][ext.buildinfo], "src/first"],
+                [Diagnostics.Building_project_0, sources[project.third][source.config]]
+            );
+            host.clearDiagnostics();
+        });
+
         describe("Prepend output with .tsbuildinfo", () => {
             // Prologues
             describe("Prologues", () => {
diff --git a/src/tsc/tsc.ts b/src/tsc/tsc.ts
index ccc04d38088d5..984ebe21cf6e6 100644
--- a/src/tsc/tsc.ts
+++ b/src/tsc/tsc.ts
@@ -165,6 +165,9 @@ namespace ts {
                 reportWatchModeWithoutSysSupport();
                 createWatchOfFilesAndCompilerOptions(commandLine.fileNames, commandLineOptions);
             }
+            else if (isIncrementalCompilation(commandLineOptions)) {
+                performIncrementalCompilation(commandLine);
+            }
             else {
                 performCompilation(commandLine.fileNames, /*references*/ undefined, commandLineOptions);
             }
diff --git a/tests/baselines/reference/incrementalConfig.js b/tests/baselines/reference/incrementalConfig.js
new file mode 100644
index 0000000000000..b90c65b9f0901
--- /dev/null
+++ b/tests/baselines/reference/incrementalConfig.js
@@ -0,0 +1,6 @@
+//// [a.ts]
+const x = 10;
+
+
+//// [a.js]
+var x = 10;
diff --git a/tests/baselines/reference/incrementalConfig.symbols b/tests/baselines/reference/incrementalConfig.symbols
new file mode 100644
index 0000000000000..05c35bcf58a68
--- /dev/null
+++ b/tests/baselines/reference/incrementalConfig.symbols
@@ -0,0 +1,4 @@
+=== /a.ts ===
+const x = 10;
+>x : Symbol(x, Decl(a.ts, 0, 5))
+
diff --git a/tests/baselines/reference/incrementalConfig.types b/tests/baselines/reference/incrementalConfig.types
new file mode 100644
index 0000000000000..ed892fed2ba10
--- /dev/null
+++ b/tests/baselines/reference/incrementalConfig.types
@@ -0,0 +1,5 @@
+=== /a.ts ===
+const x = 10;
+>x : 10
+>10 : 10
+
diff --git a/tests/baselines/reference/incrementalInvalid.errors.txt b/tests/baselines/reference/incrementalInvalid.errors.txt
new file mode 100644
index 0000000000000..6c88c5fc9d35f
--- /dev/null
+++ b/tests/baselines/reference/incrementalInvalid.errors.txt
@@ -0,0 +1,8 @@
+error TS5074: Option '--incremental' can only be specified using tsconfig, emitting to single file or when option `--tsBuildInfoFile` is specified.
+
+
+!!! error TS5074: Option '--incremental' can only be specified using tsconfig, emitting to single file or when option `--tsBuildInfoFile` is specified.
+==== tests/cases/compiler/incrementalInvalid.ts (0 errors) ====
+    const x = 10;
+    
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/incrementalInvalid.js b/tests/baselines/reference/incrementalInvalid.js
new file mode 100644
index 0000000000000..6ca4b1b2dada7
--- /dev/null
+++ b/tests/baselines/reference/incrementalInvalid.js
@@ -0,0 +1,7 @@
+//// [incrementalInvalid.ts]
+const x = 10;
+
+
+
+//// [incrementalInvalid.js]
+var x = 10;
diff --git a/tests/baselines/reference/incrementalInvalid.symbols b/tests/baselines/reference/incrementalInvalid.symbols
new file mode 100644
index 0000000000000..7a75ad5da9d2d
--- /dev/null
+++ b/tests/baselines/reference/incrementalInvalid.symbols
@@ -0,0 +1,5 @@
+=== tests/cases/compiler/incrementalInvalid.ts ===
+const x = 10;
+>x : Symbol(x, Decl(incrementalInvalid.ts, 0, 5))
+
+
diff --git a/tests/baselines/reference/incrementalInvalid.types b/tests/baselines/reference/incrementalInvalid.types
new file mode 100644
index 0000000000000..90e391222dd4b
--- /dev/null
+++ b/tests/baselines/reference/incrementalInvalid.types
@@ -0,0 +1,6 @@
+=== tests/cases/compiler/incrementalInvalid.ts ===
+const x = 10;
+>x : 10
+>10 : 10
+
+
diff --git a/tests/baselines/reference/incrementalOut.js b/tests/baselines/reference/incrementalOut.js
new file mode 100644
index 0000000000000..af73fb45a2209
--- /dev/null
+++ b/tests/baselines/reference/incrementalOut.js
@@ -0,0 +1,7 @@
+//// [incrementalOut.ts]
+const x = 10;
+
+
+
+//// [output.js]
+var x = 10;
diff --git a/tests/baselines/reference/incrementalOut.symbols b/tests/baselines/reference/incrementalOut.symbols
new file mode 100644
index 0000000000000..6ad1a4d76ee79
--- /dev/null
+++ b/tests/baselines/reference/incrementalOut.symbols
@@ -0,0 +1,5 @@
+=== tests/cases/compiler/incrementalOut.ts ===
+const x = 10;
+>x : Symbol(x, Decl(incrementalOut.ts, 0, 5))
+
+
diff --git a/tests/baselines/reference/incrementalOut.types b/tests/baselines/reference/incrementalOut.types
new file mode 100644
index 0000000000000..55b02107adf34
--- /dev/null
+++ b/tests/baselines/reference/incrementalOut.types
@@ -0,0 +1,6 @@
+=== tests/cases/compiler/incrementalOut.ts ===
+const x = 10;
+>x : 10
+>10 : 10
+
+
diff --git a/tests/baselines/reference/incrementalTsBuildInfoFile.js b/tests/baselines/reference/incrementalTsBuildInfoFile.js
new file mode 100644
index 0000000000000..cdb778d8dd551
--- /dev/null
+++ b/tests/baselines/reference/incrementalTsBuildInfoFile.js
@@ -0,0 +1,8 @@
+//// [a.ts]
+const x = 10;
+
+
+
+
+//// [a.js]
+var x = 10;
diff --git a/tests/baselines/reference/incrementalTsBuildInfoFile.symbols b/tests/baselines/reference/incrementalTsBuildInfoFile.symbols
new file mode 100644
index 0000000000000..d596c6006d7ee
--- /dev/null
+++ b/tests/baselines/reference/incrementalTsBuildInfoFile.symbols
@@ -0,0 +1,6 @@
+=== /a.ts ===
+const x = 10;
+>x : Symbol(x, Decl(a.ts, 0, 5))
+
+
+
diff --git a/tests/baselines/reference/incrementalTsBuildInfoFile.types b/tests/baselines/reference/incrementalTsBuildInfoFile.types
new file mode 100644
index 0000000000000..ab563af0e56a8
--- /dev/null
+++ b/tests/baselines/reference/incrementalTsBuildInfoFile.types
@@ -0,0 +1,7 @@
+=== /a.ts ===
+const x = 10;
+>x : 10
+>10 : 10
+
+
+
diff --git a/tests/baselines/reference/tsConfig/Default initialized TSConfig/tsconfig.json b/tests/baselines/reference/tsConfig/Default initialized TSConfig/tsconfig.json
index ec795e83e23d3..8e4ff5171868d 100644
--- a/tests/baselines/reference/tsConfig/Default initialized TSConfig/tsconfig.json	
+++ b/tests/baselines/reference/tsConfig/Default initialized TSConfig/tsconfig.json	
@@ -1,6 +1,7 @@
 {
   "compilerOptions": {
     /* Basic Options */
+    // "incremental": true,                   /* Enable incremental compilation */
     "target": "es5",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019' or 'ESNEXT'. */
     "module": "commonjs",                     /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */
     // "lib": [],                             /* Specify library files to be included in the compilation. */
@@ -14,7 +15,6 @@
     // "outDir": "./",                        /* Redirect output structure to the directory. */
     // "rootDir": "./",                       /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
     // "composite": true,                     /* Enable project compilation */
-    // "incremental": true,                   /* Enable incremental compilation */
     // "tsBuildInfoFile": "./",               /* Specify file to store incremental compilation information */
     // "removeComments": true,                /* Do not emit comments to output. */
     // "noEmit": true,                        /* Do not emit outputs. */
diff --git a/tests/baselines/reference/tsConfig/Initialized TSConfig with advanced options/tsconfig.json b/tests/baselines/reference/tsConfig/Initialized TSConfig with advanced options/tsconfig.json
index b931fe1745a65..7332496971fba 100644
--- a/tests/baselines/reference/tsConfig/Initialized TSConfig with advanced options/tsconfig.json	
+++ b/tests/baselines/reference/tsConfig/Initialized TSConfig with advanced options/tsconfig.json	
@@ -1,6 +1,7 @@
 {
   "compilerOptions": {
     /* Basic Options */
+    // "incremental": true,                   /* Enable incremental compilation */
     "target": "es5",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019' or 'ESNEXT'. */
     "module": "commonjs",                     /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */
     // "lib": [],                             /* Specify library files to be included in the compilation. */
@@ -14,7 +15,6 @@
     // "outDir": "./",                        /* Redirect output structure to the directory. */
     // "rootDir": "./",                       /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
     // "composite": true,                     /* Enable project compilation */
-    // "incremental": true,                   /* Enable incremental compilation */
     // "tsBuildInfoFile": "./",               /* Specify file to store incremental compilation information */
     // "removeComments": true,                /* Do not emit comments to output. */
     // "noEmit": true,                        /* Do not emit outputs. */
diff --git a/tests/baselines/reference/tsConfig/Initialized TSConfig with boolean value compiler options/tsconfig.json b/tests/baselines/reference/tsConfig/Initialized TSConfig with boolean value compiler options/tsconfig.json
index 6a437fd4c14b5..ebf7070cfa4d4 100644
--- a/tests/baselines/reference/tsConfig/Initialized TSConfig with boolean value compiler options/tsconfig.json	
+++ b/tests/baselines/reference/tsConfig/Initialized TSConfig with boolean value compiler options/tsconfig.json	
@@ -1,6 +1,7 @@
 {
   "compilerOptions": {
     /* Basic Options */
+    // "incremental": true,                   /* Enable incremental compilation */
     "target": "es5",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019' or 'ESNEXT'. */
     "module": "commonjs",                     /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */
     // "lib": [],                             /* Specify library files to be included in the compilation. */
@@ -14,7 +15,6 @@
     // "outDir": "./",                        /* Redirect output structure to the directory. */
     // "rootDir": "./",                       /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
     // "composite": true,                     /* Enable project compilation */
-    // "incremental": true,                   /* Enable incremental compilation */
     // "tsBuildInfoFile": "./",               /* Specify file to store incremental compilation information */
     // "removeComments": true,                /* Do not emit comments to output. */
     // "noEmit": true,                        /* Do not emit outputs. */
diff --git a/tests/baselines/reference/tsConfig/Initialized TSConfig with enum value compiler options/tsconfig.json b/tests/baselines/reference/tsConfig/Initialized TSConfig with enum value compiler options/tsconfig.json
index d1d8d42c433ad..25f9b39967a8d 100644
--- a/tests/baselines/reference/tsConfig/Initialized TSConfig with enum value compiler options/tsconfig.json	
+++ b/tests/baselines/reference/tsConfig/Initialized TSConfig with enum value compiler options/tsconfig.json	
@@ -1,6 +1,7 @@
 {
   "compilerOptions": {
     /* Basic Options */
+    // "incremental": true,                   /* Enable incremental compilation */
     "target": "es5",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019' or 'ESNEXT'. */
     "module": "commonjs",                     /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */
     // "lib": [],                             /* Specify library files to be included in the compilation. */
@@ -14,7 +15,6 @@
     // "outDir": "./",                        /* Redirect output structure to the directory. */
     // "rootDir": "./",                       /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
     // "composite": true,                     /* Enable project compilation */
-    // "incremental": true,                   /* Enable incremental compilation */
     // "tsBuildInfoFile": "./",               /* Specify file to store incremental compilation information */
     // "removeComments": true,                /* Do not emit comments to output. */
     // "noEmit": true,                        /* Do not emit outputs. */
diff --git a/tests/baselines/reference/tsConfig/Initialized TSConfig with files options/tsconfig.json b/tests/baselines/reference/tsConfig/Initialized TSConfig with files options/tsconfig.json
index c2bcb1307c1fb..fc1fb8ec631d8 100644
--- a/tests/baselines/reference/tsConfig/Initialized TSConfig with files options/tsconfig.json	
+++ b/tests/baselines/reference/tsConfig/Initialized TSConfig with files options/tsconfig.json	
@@ -1,6 +1,7 @@
 {
   "compilerOptions": {
     /* Basic Options */
+    // "incremental": true,                   /* Enable incremental compilation */
     "target": "es5",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019' or 'ESNEXT'. */
     "module": "commonjs",                     /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */
     // "lib": [],                             /* Specify library files to be included in the compilation. */
@@ -14,7 +15,6 @@
     // "outDir": "./",                        /* Redirect output structure to the directory. */
     // "rootDir": "./",                       /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
     // "composite": true,                     /* Enable project compilation */
-    // "incremental": true,                   /* Enable incremental compilation */
     // "tsBuildInfoFile": "./",               /* Specify file to store incremental compilation information */
     // "removeComments": true,                /* Do not emit comments to output. */
     // "noEmit": true,                        /* Do not emit outputs. */
diff --git a/tests/baselines/reference/tsConfig/Initialized TSConfig with incorrect compiler option value/tsconfig.json b/tests/baselines/reference/tsConfig/Initialized TSConfig with incorrect compiler option value/tsconfig.json
index 37c1960d80d36..dcff85de986d4 100644
--- a/tests/baselines/reference/tsConfig/Initialized TSConfig with incorrect compiler option value/tsconfig.json	
+++ b/tests/baselines/reference/tsConfig/Initialized TSConfig with incorrect compiler option value/tsconfig.json	
@@ -1,6 +1,7 @@
 {
   "compilerOptions": {
     /* Basic Options */
+    // "incremental": true,                   /* Enable incremental compilation */
     "target": "es5",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019' or 'ESNEXT'. */
     "module": "commonjs",                     /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */
     "lib": ["es5","es2015.promise"],          /* Specify library files to be included in the compilation. */
@@ -14,7 +15,6 @@
     // "outDir": "./",                        /* Redirect output structure to the directory. */
     // "rootDir": "./",                       /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
     // "composite": true,                     /* Enable project compilation */
-    // "incremental": true,                   /* Enable incremental compilation */
     // "tsBuildInfoFile": "./",               /* Specify file to store incremental compilation information */
     // "removeComments": true,                /* Do not emit comments to output. */
     // "noEmit": true,                        /* Do not emit outputs. */
diff --git a/tests/baselines/reference/tsConfig/Initialized TSConfig with incorrect compiler option/tsconfig.json b/tests/baselines/reference/tsConfig/Initialized TSConfig with incorrect compiler option/tsconfig.json
index ec795e83e23d3..8e4ff5171868d 100644
--- a/tests/baselines/reference/tsConfig/Initialized TSConfig with incorrect compiler option/tsconfig.json	
+++ b/tests/baselines/reference/tsConfig/Initialized TSConfig with incorrect compiler option/tsconfig.json	
@@ -1,6 +1,7 @@
 {
   "compilerOptions": {
     /* Basic Options */
+    // "incremental": true,                   /* Enable incremental compilation */
     "target": "es5",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019' or 'ESNEXT'. */
     "module": "commonjs",                     /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */
     // "lib": [],                             /* Specify library files to be included in the compilation. */
@@ -14,7 +15,6 @@
     // "outDir": "./",                        /* Redirect output structure to the directory. */
     // "rootDir": "./",                       /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
     // "composite": true,                     /* Enable project compilation */
-    // "incremental": true,                   /* Enable incremental compilation */
     // "tsBuildInfoFile": "./",               /* Specify file to store incremental compilation information */
     // "removeComments": true,                /* Do not emit comments to output. */
     // "noEmit": true,                        /* Do not emit outputs. */
diff --git a/tests/baselines/reference/tsConfig/Initialized TSConfig with list compiler options with enum value/tsconfig.json b/tests/baselines/reference/tsConfig/Initialized TSConfig with list compiler options with enum value/tsconfig.json
index bc24243c11f5c..112be7a95f953 100644
--- a/tests/baselines/reference/tsConfig/Initialized TSConfig with list compiler options with enum value/tsconfig.json	
+++ b/tests/baselines/reference/tsConfig/Initialized TSConfig with list compiler options with enum value/tsconfig.json	
@@ -1,6 +1,7 @@
 {
   "compilerOptions": {
     /* Basic Options */
+    // "incremental": true,                   /* Enable incremental compilation */
     "target": "es5",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019' or 'ESNEXT'. */
     "module": "commonjs",                     /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */
     "lib": ["es5","es2015.core"],             /* Specify library files to be included in the compilation. */
@@ -14,7 +15,6 @@
     // "outDir": "./",                        /* Redirect output structure to the directory. */
     // "rootDir": "./",                       /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
     // "composite": true,                     /* Enable project compilation */
-    // "incremental": true,                   /* Enable incremental compilation */
     // "tsBuildInfoFile": "./",               /* Specify file to store incremental compilation information */
     // "removeComments": true,                /* Do not emit comments to output. */
     // "noEmit": true,                        /* Do not emit outputs. */
diff --git a/tests/baselines/reference/tsConfig/Initialized TSConfig with list compiler options/tsconfig.json b/tests/baselines/reference/tsConfig/Initialized TSConfig with list compiler options/tsconfig.json
index 1c16ed114165f..4c4b740a12284 100644
--- a/tests/baselines/reference/tsConfig/Initialized TSConfig with list compiler options/tsconfig.json	
+++ b/tests/baselines/reference/tsConfig/Initialized TSConfig with list compiler options/tsconfig.json	
@@ -1,6 +1,7 @@
 {
   "compilerOptions": {
     /* Basic Options */
+    // "incremental": true,                   /* Enable incremental compilation */
     "target": "es5",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019' or 'ESNEXT'. */
     "module": "commonjs",                     /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */
     // "lib": [],                             /* Specify library files to be included in the compilation. */
@@ -14,7 +15,6 @@
     // "outDir": "./",                        /* Redirect output structure to the directory. */
     // "rootDir": "./",                       /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
     // "composite": true,                     /* Enable project compilation */
-    // "incremental": true,                   /* Enable incremental compilation */
     // "tsBuildInfoFile": "./",               /* Specify file to store incremental compilation information */
     // "removeComments": true,                /* Do not emit comments to output. */
     // "noEmit": true,                        /* Do not emit outputs. */
diff --git a/tests/cases/compiler/incrementalConfig.ts b/tests/cases/compiler/incrementalConfig.ts
new file mode 100644
index 0000000000000..6ed172c837a68
--- /dev/null
+++ b/tests/cases/compiler/incrementalConfig.ts
@@ -0,0 +1,8 @@
+// @incremental: true
+
+// @Filename: /a.ts
+const x = 10;
+
+// @Filename: /tsconfig.json
+{ }
+
diff --git a/tests/cases/compiler/incrementalInvalid.ts b/tests/cases/compiler/incrementalInvalid.ts
new file mode 100644
index 0000000000000..4a7c3e72de96e
--- /dev/null
+++ b/tests/cases/compiler/incrementalInvalid.ts
@@ -0,0 +1,4 @@
+// @incremental: true
+
+const x = 10;
+
diff --git a/tests/cases/compiler/incrementalOut.ts b/tests/cases/compiler/incrementalOut.ts
new file mode 100644
index 0000000000000..4cd49dbba112d
--- /dev/null
+++ b/tests/cases/compiler/incrementalOut.ts
@@ -0,0 +1,5 @@
+// @incremental: true
+// @out: output.js
+
+const x = 10;
+
diff --git a/tests/cases/compiler/incrementalTsBuildInfoFile.ts b/tests/cases/compiler/incrementalTsBuildInfoFile.ts
new file mode 100644
index 0000000000000..51a9661187cb6
--- /dev/null
+++ b/tests/cases/compiler/incrementalTsBuildInfoFile.ts
@@ -0,0 +1,8 @@
+// @incremental: true
+// @tsBuildInfoFile: /a.tsbuildinfo
+
+
+// @Filename: /a.ts
+const x = 10;
+
+
diff --git a/tests/cases/fourslash/addMemberInDeclarationFile.ts b/tests/cases/fourslash/addMemberInDeclarationFile.ts
new file mode 100644
index 0000000000000..1d2e900512db8
--- /dev/null
+++ b/tests/cases/fourslash/addMemberInDeclarationFile.ts
@@ -0,0 +1,17 @@
+/// <reference path="fourslash.ts" />
+
+// @Filename: ./declarations.d.ts
+//// interface Response {}
+
+// @Filename: foo.ts
+//// import './declarations.d.ts'
+//// declare const resp: Response
+//// resp.test()
+
+goTo.file('foo.ts')
+
+verify.codeFixAvailable([
+    { description: "Declare method 'test'" },
+    { description: "Declare property 'test'" },
+    { description: "Add index signature for property 'test'" }
+])
diff --git a/tests/cases/fourslash/addMemberNotInNodeModulesDeclarationFile.ts b/tests/cases/fourslash/addMemberNotInNodeModulesDeclarationFile.ts
new file mode 100644
index 0000000000000..3a97aeac6dd84
--- /dev/null
+++ b/tests/cases/fourslash/addMemberNotInNodeModulesDeclarationFile.ts
@@ -0,0 +1,19 @@
+/// <reference path="fourslash.ts" />
+
+// @noImplicitReferences: true
+// @traceResolution: true
+
+// @Filename: /node_modules/foo/types.d.ts
+//// interface Response {}
+
+// @Filename: /node_modules/foo/package.json
+//// { "types": "types.d.ts" }
+
+// @Filename: /foo.ts
+//// import { Response } from 'foo'
+//// declare const resp: Response
+//// resp.test()
+
+goTo.file('/foo.ts')
+
+verify.not.codeFixAvailable()