diff --git a/appmesh-preview/service-model.json b/appmesh-preview/service-model.json
index c5ba6cd..e04a4e1 100644
--- a/appmesh-preview/service-model.json
+++ b/appmesh-preview/service-model.json
@@ -1248,6 +1248,30 @@
       "min": 0,
       "max": 50
     },
+    "GrpcRetryPolicy": {
+      "type": "structure",
+      "required": [
+        "maxRetries",
+        "perRetryTimeout"
+      ],
+      "members": {
+        "grpcRetryEvents": {
+          "shape": "GrpcRetryPolicyEvents"
+        },
+        "httpRetryEvents": {
+          "shape": "HttpRetryPolicyEvents"
+        },
+        "maxRetries": {
+          "shape": "MaxRetries"
+        },
+        "perRetryTimeout": {
+          "shape": "Duration"
+        },
+        "tcpRetryEvents": {
+          "shape": "TcpRetryPolicyEvents"
+        }
+      }
+    },
     "ListTagsForResourceInput": {
       "type": "structure",
       "required": [
@@ -1299,6 +1323,14 @@
       },
       "documentation": "<p>An object representing the logging information for a virtual node.</p>"
     },
+    "GrpcRetryPolicyEvents": {
+      "type": "list",
+      "member": {
+        "shape": "GrpcRetryPolicyEvent"
+      },
+      "min": 1,
+      "max": 5
+    },
     "ServiceUnavailableException": {
       "type": "structure",
       "members": {
@@ -1495,7 +1527,9 @@
     "PortProtocol": {
       "type": "string",
       "enum": [
+        "grpc",
         "http",
+        "http2",
         "tcp"
       ]
     },
@@ -1552,7 +1586,9 @@
       ]
     },
     "ServiceName": {
-      "type": "string"
+      "type": "string",
+      "min": 1,
+      "max": 50
     },
     "BadRequestException": {
       "type": "structure",
@@ -1625,6 +1661,14 @@
       "min": 0,
       "max": 100
     },
+    "GrpcRouteMetadataList": {
+      "type": "list",
+      "member": {
+        "shape": "GrpcRouteMetadata"
+      },
+      "min": 1,
+      "max": 10
+    },
     "ListenerTlsMode": {
       "type": "string",
       "enum": [
@@ -1633,6 +1677,11 @@
         "STRICT"
       ]
     },
+    "MethodName": {
+      "type": "string",
+      "min": 1,
+      "max": 50
+    },
     "TagValue": {
       "type": "string",
       "min": 0,
@@ -1940,6 +1989,17 @@
       },
       "documentation": ""
     },
+    "GrpcRouteAction": {
+      "type": "structure",
+      "required": [
+        "weightedTargets"
+      ],
+      "members": {
+        "weightedTargets": {
+          "shape": "WeightedTargets"
+        }
+      }
+    },
     "DescribeVirtualNodeOutput": {
       "type": "structure",
       "required": [
@@ -2002,6 +2062,26 @@
       "documentation": "",
       "payload": "route"
     },
+    "GrpcRouteMetadataMatchMethod": {
+      "type": "structure",
+      "members": {
+        "exact": {
+          "shape": "HeaderMatch"
+        },
+        "prefix": {
+          "shape": "HeaderMatch"
+        },
+        "range": {
+          "shape": "MatchRange"
+        },
+        "regex": {
+          "shape": "HeaderMatch"
+        },
+        "suffix": {
+          "shape": "HeaderMatch"
+        }
+      }
+    },
     "DnsServiceDiscovery": {
       "type": "structure",
       "required": [
@@ -2623,12 +2703,15 @@
       "type": "structure",
       "members": {
         "unit": {
-          "shape": "DurationUnit"
+          "shape": "DurationUnit",
+          "documentation": "<p>A unit of time.</p>"
         },
         "value": {
-          "shape": "DurationValue"
+          "shape": "DurationValue",
+          "documentation": "<p>A number of time units.</p>"
         }
-      }
+      },
+      "documentation": "<p>An object representing a duration of time.</p>"
     },
     "ConflictException": {
       "type": "structure",
@@ -2937,6 +3020,24 @@
       },
       "documentation": "<p>An object representing a listener for a virtual node.</p>"
     },
+    "GrpcRoute": {
+      "type": "structure",
+      "required": [
+        "action",
+        "match"
+      ],
+      "members": {
+        "action": {
+          "shape": "GrpcRouteAction"
+        },
+        "match": {
+          "shape": "GrpcRouteMatch"
+        },
+        "retryPolicy": {
+          "shape": "GrpcRetryPolicy"
+        }
+      }
+    },
     "DeleteVirtualNodeInput": {
       "type": "structure",
       "required": [
@@ -3066,6 +3167,16 @@
       "min": 0,
       "max": 50
     },
+    "GrpcRetryPolicyEvent": {
+      "type": "string",
+      "enum": [
+        "cancelled",
+        "deadline-exceeded",
+        "internal",
+        "resource-exhausted",
+        "unavailable"
+      ]
+    },
     "HttpRetryPolicy": {
       "type": "structure",
       "required": [
@@ -3074,18 +3185,23 @@
       ],
       "members": {
         "httpRetryEvents": {
-          "shape": "HttpRetryPolicyEvents"
+          "shape": "HttpRetryPolicyEvents",
+          "documentation": "<p>Specify at least one of the following values.</p>\n         <ul>\n            <li>\n               <p>\n                  <b>server-error</b> – HTTP status codes 500, 501,\n               502, 503, 504, 505, 506, 507, 508, 510, and 511</p>\n            </li>\n            <li>\n               <p>\n                  <b>gateway-error</b> – HTTP status codes 502,\n               503, and 504</p>\n            </li>\n            <li>\n               <p>\n                  <b>client-error</b> – HTTP status code 409</p>\n            </li>\n            <li>\n               <p>\n                  <b>stream-error</b> – Retry on refused\n               stream</p>\n            </li>\n         </ul>"
         },
         "maxRetries": {
-          "shape": "MaxRetries"
+          "shape": "MaxRetries",
+          "documentation": "<p>The maximum number of retry attempts. If no value is specified, the default is 1.</p>"
         },
         "perRetryTimeout": {
-          "shape": "Duration"
+          "shape": "Duration",
+          "documentation": "<p>An object that represents the duration of time between retries.</p>"
         },
         "tcpRetryEvents": {
-          "shape": "TcpRetryPolicyEvents"
+          "shape": "TcpRetryPolicyEvents",
+          "documentation": "<p>Specify a valid value.</p>"
         }
-      }
+      },
+      "documentation": "<p>An object that represents a retry policy.</p>"
     },
     "DescribeVirtualRouterInput": {
       "type": "structure",
@@ -3230,6 +3346,23 @@
       },
       "documentation": ""
     },
+    "GrpcRouteMetadata": {
+      "type": "structure",
+      "required": [
+        "name"
+      ],
+      "members": {
+        "invert": {
+          "shape": "Boolean"
+        },
+        "match": {
+          "shape": "GrpcRouteMetadataMatchMethod"
+        },
+        "name": {
+          "shape": "HeaderName"
+        }
+      }
+    },
     "CreateRouteInput": {
       "type": "structure",
       "required": [
@@ -3301,6 +3434,20 @@
       },
       "documentation": "<p>An object representing the provider for a virtual service.</p>"
     },
+    "GrpcRouteMatch": {
+      "type": "structure",
+      "members": {
+        "metadata": {
+          "shape": "GrpcRouteMetadataList"
+        },
+        "methodName": {
+          "shape": "MethodName"
+        },
+        "serviceName": {
+          "shape": "ServiceName"
+        }
+      }
+    },
     "String": {
       "type": "string"
     },
@@ -3448,6 +3595,18 @@
     "RouteSpec": {
       "type": "structure",
       "members": {
+        "grpcRoute": {
+          "shape": "GrpcRoute",
+          "tags": [
+            "preview"
+          ]
+        },
+        "http2Route": {
+          "shape": "HttpRoute",
+          "tags": [
+            "preview"
+          ]
+        },
         "httpRoute": {
           "shape": "HttpRoute",
           "documentation": "<p>The HTTP routing information for the route.</p>"
@@ -3480,9 +3639,7 @@
         },
         "retryPolicy": {
           "shape": "HttpRetryPolicy",
-          "tags": [
-            "preview"
-          ]
+          "documentation": "<p>An object that represents a retry policy.</p>"
         }
       },
       "documentation": "<p>An object representing the HTTP routing specification for a route.</p>"