diff --git a/specification/containerservices/resource-manager/Microsoft.ContainerService/stable/2018-03-31/examples/ManagedClustersUpdateTags.json b/specification/containerservices/resource-manager/Microsoft.ContainerService/stable/2018-03-31/examples/ManagedClustersUpdateTags.json
new file mode 100644
index 000000000000..a34864c4c62d
--- /dev/null
+++ b/specification/containerservices/resource-manager/Microsoft.ContainerService/stable/2018-03-31/examples/ManagedClustersUpdateTags.json
@@ -0,0 +1,66 @@
+{
+  "parameters": {
+    "api-version": "2018-03-31",
+    "subscriptionId": "subid1",
+    "resourceGroupName": "rg1",
+    "resourceName": "clustername1",
+    "parameters": {
+      "tags": {
+        "tier": "testing",
+        "archv3": ""
+      }
+    }
+  },
+  "responses": {
+    "200": {
+      "body": {
+        "id": "/subscriptions/subid1/resourcegroups/rg1/providers/Microsoft.ContainerService/managedClusters/clustername1",
+        "location": "location1",
+        "name": "clustername1",
+        "tags": {
+          "archv3": "",
+          "tier": "testing"
+        },
+        "type": "Microsoft.ContainerService/ManagedClusters",
+        "properties": {
+          "provisioningState": "Succeeded",
+          "kubernetesVersion": "1.9.6",
+          "dnsPrefix": "dnsprefix1",
+          "agentPoolProfiles": [
+            {
+              "name": "nodepool1",
+              "count": 3,
+              "vmSize": "Standard_DS1_v2",
+              "storageProfile": "ManagedDisks",
+              "maxPods": 110,
+              "osType": "Linux"
+            }
+          ],
+          "linuxProfile": {
+            "adminUsername": "azureuser",
+            "ssh": {
+              "publicKeys": [
+                {
+                  "keyData": "keydata"
+                }
+              ]
+            }
+          },
+          "servicePrincipalProfile": {
+            "clientId": "clientid"
+          },
+          "nodeResourceGroup": "MC_rg1_clustername1_location1",
+          "enableRBAC": false,
+          "fqdn": "dnsprefix1-abcd1234.hcp.eastus.azmk8s.io",
+          "networkProfile": {
+            "networkPlugin": "kubenet",
+            "podCidr": "10.244.0.0/16",
+            "serviceCidr": "10.0.0.0/16",
+            "dnsServiceIP": "10.0.0.10",
+            "dockerBridgeCidr": "172.17.0.1/16"
+          }
+        }
+      }
+    }
+  }
+}
diff --git a/specification/containerservices/resource-manager/Microsoft.ContainerService/stable/2018-03-31/managedClusters.json b/specification/containerservices/resource-manager/Microsoft.ContainerService/stable/2018-03-31/managedClusters.json
index 530d696ed6be..b53f6cb77a24 100644
--- a/specification/containerservices/resource-manager/Microsoft.ContainerService/stable/2018-03-31/managedClusters.json
+++ b/specification/containerservices/resource-manager/Microsoft.ContainerService/stable/2018-03-31/managedClusters.json
@@ -334,6 +334,59 @@
           }
         }
       },
+      "patch": {
+        "tags": [
+          "ManagedClusters"
+        ],
+        "operationId": "ManagedClusters_UpdateTags",
+        "summary": "Updates tags on a managed cluster.",
+        "description": "Updates a managed cluster with the specified tags.",
+        "parameters": [
+          {
+            "$ref": "#/parameters/ApiVersionParameter"
+          },
+          {
+            "$ref": "#/parameters/SubscriptionIdParameter"
+          },
+          {
+            "name": "resourceGroupName",
+            "in": "path",
+            "required": true,
+            "type": "string",
+            "description": "The name of the resource group."
+          },
+          {
+            "name": "resourceName",
+            "in": "path",
+            "required": true,
+            "type": "string",
+            "description": "The name of the managed cluster resource."
+          },
+          {
+            "name": "parameters",
+            "in": "body",
+            "required": true,
+            "schema": {
+              "$ref": "#/definitions/TagsObject"
+            },
+            "description": "Parameters supplied to the Update Managed Cluster Tags operation."
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "OK",
+            "schema": {
+              "$ref": "#/definitions/ManagedCluster"
+            }
+          }
+        },
+        "x-ms-long-running-operation": true,
+        "x-ms-examples": {
+          "Update Managed Cluster Tags": {
+            "$ref": "./examples/ManagedClustersUpdateTags.json"
+          }
+        }
+      },
       "delete": {
         "tags": [
           "ManagedClusters"
@@ -478,6 +531,18 @@
       ],
       "x-ms-azure-resource": true
     },
+    "TagsObject": {
+      "properties": {
+        "tags": {
+          "type": "object",
+          "additionalProperties": {
+            "type": "string"
+          },
+          "description": "Resource tags."
+        }
+      },
+      "description": "Tags object for patch operations."
+    },
     "ContainerServiceOSDisk": {
       "type": "integer",
       "format": "int32",
@@ -486,7 +551,6 @@
       "description": "OS Disk Size in GB to be used to specify the disk size for every machine in this master/agent pool. If you specify 0, it will apply the default osDisk size according to the vmSize specified."
     },
     "ContainerServiceStorageProfile": {
-
       "type": "string",
       "x-ms-enum": {
         "name": "ContainerServiceStorageProfileTypes",