diff --git a/x-pack/plugins/ml/common/constants/annotations.ts b/x-pack/plugins/ml/common/constants/annotations.ts
index 96367682ecf0..c27a4f620be6 100644
--- a/x-pack/plugins/ml/common/constants/annotations.ts
+++ b/x-pack/plugins/ml/common/constants/annotations.ts
@@ -8,3 +8,6 @@ export enum ANNOTATION_TYPE {
   ANNOTATION = 'annotation',
   COMMENT = 'comment',
 }
+
+export const ANNOTATION_DOC_TYPE = 'doc';
+export const ANNOTATION_USER_UNKNOWN = '<user unknown>';
diff --git a/x-pack/plugins/ml/index.js b/x-pack/plugins/ml/index.js
index cbcb0ddb52f3..96e489fa307c 100644
--- a/x-pack/plugins/ml/index.js
+++ b/x-pack/plugins/ml/index.js
@@ -9,7 +9,8 @@
 import { resolve } from 'path';
 import Boom from 'boom';
 import { checkLicense } from './server/lib/check_license';
-import { isAnnotationsFeatureAvailable } from './server/lib/check_annotations';
+import { FEATURE_ANNOTATIONS_ENABLED } from './common/constants/feature_flags';
+
 import { mirrorPluginStatus } from '../../server/lib/mirror_plugin_status';
 import { annotationRoutes } from './server/routes/annotations';
 import { jobRoutes } from './server/routes/anomaly_detectors';
@@ -78,13 +79,11 @@ export const ml = (kibana) => {
         ]
       };
 
-      const mlAnnotationsEnabled = await isAnnotationsFeatureAvailable(server);
-
       server.injectUiAppVars('ml', () => {
         const config = server.config();
         return {
           kbnIndex: config.get('kibana.index'),
-          mlAnnotationsEnabled,
+          mlAnnotationsEnabled: FEATURE_ANNOTATIONS_ENABLED,
         };
       });
 
diff --git a/x-pack/plugins/ml/public/timeseriesexplorer/components/timeseries_chart/timeseries_chart.js b/x-pack/plugins/ml/public/timeseriesexplorer/components/timeseries_chart/timeseries_chart.js
index 3117a56beb0c..26a6b7435774 100644
--- a/x-pack/plugins/ml/public/timeseriesexplorer/components/timeseries_chart/timeseries_chart.js
+++ b/x-pack/plugins/ml/public/timeseriesexplorer/components/timeseries_chart/timeseries_chart.js
@@ -1353,7 +1353,7 @@ export class TimeseriesChart extends React.Component {
     }
 
     if (mlAnnotationsEnabled && _.has(marker, 'annotation')) {
-      contents = marker.annotation;
+      contents = mlEscape(marker.annotation);
       contents += `<br />${moment(marker.timestamp).format('MMMM Do YYYY, HH:mm')}`;
 
       if (typeof marker.end_timestamp !== 'undefined') {
diff --git a/x-pack/plugins/ml/server/models/annotation_service/annotation.ts b/x-pack/plugins/ml/server/models/annotation_service/annotation.ts
index d642b509f317..a05b57572116 100644
--- a/x-pack/plugins/ml/server/models/annotation_service/annotation.ts
+++ b/x-pack/plugins/ml/server/models/annotation_service/annotation.ts
@@ -7,7 +7,7 @@
 import Boom from 'boom';
 import _ from 'lodash';
 
-import { ANNOTATION_TYPE } from '../../../common/constants/annotations';
+import { ANNOTATION_DOC_TYPE, ANNOTATION_TYPE } from '../../../common/constants/annotations';
 import {
   ML_ANNOTATIONS_INDEX_ALIAS_READ,
   ML_ANNOTATIONS_INDEX_ALIAS_WRITE,
@@ -63,22 +63,22 @@ interface DeleteParams {
 export function annotationProvider(
   callWithRequest: (action: string, params: IndexParams | DeleteParams | GetParams) => Promise<any>
 ) {
-  async function indexAnnotation(annotation: Annotation) {
+  async function indexAnnotation(annotation: Annotation, username: string) {
     if (isAnnotation(annotation) === false) {
       return Promise.reject(new Error('invalid annotation format'));
     }
 
     if (annotation.create_time === undefined) {
       annotation.create_time = new Date().getTime();
-      annotation.create_username = '<user unknown>';
+      annotation.create_username = username;
     }
 
     annotation.modified_time = new Date().getTime();
-    annotation.modified_username = '<user unknown>';
+    annotation.modified_username = username;
 
     const params: IndexParams = {
       index: ML_ANNOTATIONS_INDEX_ALIAS_WRITE,
-      type: 'annotation',
+      type: ANNOTATION_DOC_TYPE,
       body: annotation,
       refresh: 'wait_for',
     };
@@ -232,7 +232,7 @@ export function annotationProvider(
   async function deleteAnnotation(id: string) {
     const param: DeleteParams = {
       index: ML_ANNOTATIONS_INDEX_ALIAS_WRITE,
-      type: 'annotation',
+      type: ANNOTATION_DOC_TYPE,
       id,
       refresh: 'wait_for',
     };
diff --git a/x-pack/plugins/ml/server/routes/annotations.js b/x-pack/plugins/ml/server/routes/annotations.js
index f9f319957681..bfb3a439a30d 100644
--- a/x-pack/plugins/ml/server/routes/annotations.js
+++ b/x-pack/plugins/ml/server/routes/annotations.js
@@ -4,12 +4,14 @@
  * you may not use this file except in compliance with the Elastic License.
  */
 
-
+import _ from 'lodash';
 
 import { callWithRequestFactory } from '../client/call_with_request_factory';
 import { wrapError } from '../client/errors';
 import { annotationServiceProvider } from '../models/annotation_service';
 
+import { ANNOTATION_USER_UNKNOWN } from '../../common/constants/annotations';
+
 export function annotationRoutes(server, commonRouteConfig) {
   server.route({
     method: 'POST',
@@ -31,7 +33,8 @@ export function annotationRoutes(server, commonRouteConfig) {
     handler(request) {
       const callWithRequest = callWithRequestFactory(server, request);
       const { indexAnnotation } = annotationServiceProvider(callWithRequest);
-      return indexAnnotation(request.payload)
+      const username = _.get(request, 'auth.credentials.username', ANNOTATION_USER_UNKNOWN);
+      return indexAnnotation(request.payload, username)
         .catch(resp => wrapError(resp));
     },
     config: {