diff --git a/specification/search/data-plane/Microsoft.Azure.Search.Data/preview/2017-11-11-preview/examples/SearchIndexAutocompleteDocumentsGet.json b/specification/search/data-plane/Microsoft.Azure.Search.Data/preview/2017-11-11-preview/examples/SearchIndexAutocompleteDocumentsGet.json
index 1ce59bf94eec..cff713cb9273 100644
--- a/specification/search/data-plane/Microsoft.Azure.Search.Data/preview/2017-11-11-preview/examples/SearchIndexAutocompleteDocumentsGet.json
+++ b/specification/search/data-plane/Microsoft.Azure.Search.Data/preview/2017-11-11-preview/examples/SearchIndexAutocompleteDocumentsGet.json
@@ -7,6 +7,7 @@
         "autocompleteMode": "oneTerm",
         "search": "washington medic",
         "suggesterName": "sg",
+        "filter": "search.in(docId,'101,102,105')",
         "fuzzy": false,
         "highlightPostTag": "</em>",
         "highlightPreTag": "<em>",
diff --git a/specification/search/data-plane/Microsoft.Azure.Search.Data/preview/2017-11-11-preview/examples/SearchIndexAutocompleteDocumentsPost.json b/specification/search/data-plane/Microsoft.Azure.Search.Data/preview/2017-11-11-preview/examples/SearchIndexAutocompleteDocumentsPost.json
index e693f6f07de8..30f0b05d39f0 100644
--- a/specification/search/data-plane/Microsoft.Azure.Search.Data/preview/2017-11-11-preview/examples/SearchIndexAutocompleteDocumentsPost.json
+++ b/specification/search/data-plane/Microsoft.Azure.Search.Data/preview/2017-11-11-preview/examples/SearchIndexAutocompleteDocumentsPost.json
@@ -8,6 +8,7 @@
           "autocompleteMode": "oneTerm",
           "search": "washington medic",
           "suggesterName": "sg",
+          "filter": "search.in(docId,'101,102,105')",
           "highlightPostTag": "</em>",
           "highlightPreTag": "<em>",
           "minimumCoverage": 80,
diff --git a/specification/search/data-plane/Microsoft.Azure.Search.Data/preview/2017-11-11-preview/searchindex.json b/specification/search/data-plane/Microsoft.Azure.Search.Data/preview/2017-11-11-preview/searchindex.json
index 9fe0df3e329f..d6081f45d3ac 100644
--- a/specification/search/data-plane/Microsoft.Azure.Search.Data/preview/2017-11-11-preview/searchindex.json
+++ b/specification/search/data-plane/Microsoft.Azure.Search.Data/preview/2017-11-11-preview/searchindex.json
@@ -238,7 +238,7 @@
              "name": "SearchMode",
              "modelAsString": false
             },
-            "x-nullable": false,            
+            "x-nullable": false,
             "description": "A value that specifies whether any or all of the search terms must be matched in order to count the document as a match.",
             "x-ms-parameter-grouping": {
               "name": "SearchParameters"
@@ -341,7 +341,7 @@
         "tags": [
           "Documents"
         ],
-        "operationId": "Documents_Get",        
+        "operationId": "Documents_Get",
         "externalDocs": {
           "url": "https://docs.microsoft.com/rest/api/searchservice/lookup-document"
         },
@@ -392,7 +392,7 @@
         "operationId": "Documents_SuggestGet",
         "externalDocs": {
           "url": "https://docs.microsoft.com/rest/api/searchservice/suggestions"
-        },        
+        },
         "x-ms-examples": {
           "SearchIndexSuggestDocumentsGet": { "$ref": "./examples/SearchIndexSuggestDocumentsGet.json" }
         },
@@ -578,7 +578,7 @@
         },
         "x-ms-examples": {
           "SearchIndexIndexDocuments": { "$ref": "./examples/SearchIndexIndexDocuments.json" }
-        },        
+        },
         "description": "Sends a batch of document write actions to the Azure Search index.",
         "parameters": [
           {
@@ -668,6 +668,15 @@
               "name": "AutocompleteParameters"
             }
           },
+          {
+            "name": "$filter",
+            "in": "query",
+            "type": "string",
+            "description": "An OData expression that filters the documents used to produce completed terms for the Autocomplete result.",
+            "x-ms-parameter-grouping": {
+              "name": "AutocompleteParameters"
+            }
+          },
           {
             "name": "fuzzy",
             "in": "query",
@@ -1181,6 +1190,13 @@
           "$ref": "#/definitions/AutocompleteMode",
           "description": "Specifies the mode for Autocomplete. The default is 'oneTerm'. Use 'twoTerms' to get shingles and 'oneTermWithContext' to use the current context while producing auto-completed terms."
         },
+        "filter": {
+          "externalDocs": {
+            "url": "https://docs.microsoft.com/rest/api/searchservice/OData-Expression-Syntax-for-Azure-Search"
+          },
+          "type": "string",
+          "description": "An OData expression that filters the documents used to produce completed terms for the Autocomplete result."
+        },
         "fuzzy": {
           "type": "boolean",
           "description": "A value indicating whether to use fuzzy matching for the autocomplete query. Default is false. When set to true, the query will autocomplete terms even if there's a substituted or missing character in the search text. While this provides a better experience in some scenarios, it comes at a performance cost as fuzzy autocomplete queries are slower and consume more resources.",