diff --git a/specification/containerservice/resource-manager/Microsoft.ContainerService/stable/2020-07-01/examples/AgentPoolsUpgradeNodeImageVersion.json b/specification/containerservice/resource-manager/Microsoft.ContainerService/stable/2020-07-01/examples/AgentPoolsUpgradeNodeImageVersion.json
new file mode 100644
index 000000000000..2c069e0f7d05
--- /dev/null
+++ b/specification/containerservice/resource-manager/Microsoft.ContainerService/stable/2020-07-01/examples/AgentPoolsUpgradeNodeImageVersion.json
@@ -0,0 +1,30 @@
+{
+  "parameters": {
+    "api-version": "2020-07-01",
+    "subscriptionId": "subid1",
+    "resourceGroupName": "rg1",
+    "resourceName": "clustername1",
+    "agentPoolName": "agentpool1"
+  },
+  "responses": {
+    "200": {},
+    "202": {
+      "body": {
+        "id": "/subscriptions/subid1/resourcegroups/rg1/providers/Microsoft.ContainerService/managedClusters/clustername1/agentPools/agentpool1",
+        "name": "agentpool1",
+        "properties": {
+          "provisioningState": "UpgradingNodeImageVersion",
+          "count": 3,
+          "vmSize": "Standard_DS1_v2",
+          "maxPods": 110,
+          "osType": "Linux",
+          "orchestratorVersion": "1.9.6",
+          "nodeImageVersion": "AKSUbuntu-1604-2020.03.11",
+          "upgradeSettings": {
+            "maxSurge": "33%"
+          }
+        }
+      }
+    }
+  }
+}
diff --git a/specification/containerservice/resource-manager/Microsoft.ContainerService/stable/2020-07-01/examples/ManagedClustersCreate_PPG.json b/specification/containerservice/resource-manager/Microsoft.ContainerService/stable/2020-07-01/examples/ManagedClustersCreate_PPG.json
index 0be1e69526d7..d13c0a2cfdba 100644
--- a/specification/containerservice/resource-manager/Microsoft.ContainerService/stable/2020-07-01/examples/ManagedClustersCreate_PPG.json
+++ b/specification/containerservice/resource-manager/Microsoft.ContainerService/stable/2020-07-01/examples/ManagedClustersCreate_PPG.json
@@ -26,7 +26,6 @@
             "type": "VirtualMachineScaleSets",
             "enableNodePublicIP": true,
             "mode": "System",
-            "nodeImageVersion": "AKSUbuntu:1604:2020.03.11",
             "proximityPlacementGroupID": "/subscriptions/subid1/resourcegroups/rg1/providers//Microsoft.Compute/proximityPlacementGroups/ppg1"
           }
         ],
diff --git a/specification/containerservice/resource-manager/Microsoft.ContainerService/stable/2020-07-01/examples/ManagedClustersCreate_Update.json b/specification/containerservice/resource-manager/Microsoft.ContainerService/stable/2020-07-01/examples/ManagedClustersCreate_Update.json
index d4d626b6cc27..ae067af5d51d 100644
--- a/specification/containerservice/resource-manager/Microsoft.ContainerService/stable/2020-07-01/examples/ManagedClustersCreate_Update.json
+++ b/specification/containerservice/resource-manager/Microsoft.ContainerService/stable/2020-07-01/examples/ManagedClustersCreate_Update.json
@@ -30,8 +30,7 @@
               "3"
             ],
             "enableNodePublicIP": true,
-            "mode": "System",
-            "nodeImageVersion": "AKSUbuntu:1604:2020.03.11"
+            "mode": "System"
           }
         ],
         "linuxProfile": {
diff --git a/specification/containerservice/resource-manager/Microsoft.ContainerService/stable/2020-07-01/examples/ManagedClustersCreate_UpdateWithAHUB.json b/specification/containerservice/resource-manager/Microsoft.ContainerService/stable/2020-07-01/examples/ManagedClustersCreate_UpdateWithAHUB.json
index c938c6176721..07220a608e8d 100644
--- a/specification/containerservice/resource-manager/Microsoft.ContainerService/stable/2020-07-01/examples/ManagedClustersCreate_UpdateWithAHUB.json
+++ b/specification/containerservice/resource-manager/Microsoft.ContainerService/stable/2020-07-01/examples/ManagedClustersCreate_UpdateWithAHUB.json
@@ -30,8 +30,7 @@
               "3"
             ],
             "enableNodePublicIP": true,
-            "mode": "System",
-            "nodeImageVersion": "AKSUbuntu:1604:2020.03.11"
+            "mode": "System"
           }
         ],
         "linuxProfile": {
diff --git a/specification/containerservice/resource-manager/Microsoft.ContainerService/stable/2020-07-01/examples/ManagedClustersCreate_UpdateWithEnableAzureRBAC.json b/specification/containerservice/resource-manager/Microsoft.ContainerService/stable/2020-07-01/examples/ManagedClustersCreate_UpdateWithEnableAzureRBAC.json
index 2572e869d209..e3fd532bc1bf 100644
--- a/specification/containerservice/resource-manager/Microsoft.ContainerService/stable/2020-07-01/examples/ManagedClustersCreate_UpdateWithEnableAzureRBAC.json
+++ b/specification/containerservice/resource-manager/Microsoft.ContainerService/stable/2020-07-01/examples/ManagedClustersCreate_UpdateWithEnableAzureRBAC.json
@@ -30,8 +30,7 @@
               "3"
             ],
             "enableNodePublicIP": true,
-            "mode": "System",
-            "nodeImageVersion": "AKSUbuntu:1604:2020.03.11"
+            "mode": "System"
           }
         ],
         "linuxProfile": {
diff --git a/specification/containerservice/resource-manager/Microsoft.ContainerService/stable/2020-07-01/managedClusters.json b/specification/containerservice/resource-manager/Microsoft.ContainerService/stable/2020-07-01/managedClusters.json
index 478cf10149e0..14b7db1b5c8d 100644
--- a/specification/containerservice/resource-manager/Microsoft.ContainerService/stable/2020-07-01/managedClusters.json
+++ b/specification/containerservice/resource-manager/Microsoft.ContainerService/stable/2020-07-01/managedClusters.json
@@ -1226,6 +1226,60 @@
           }
         }
       }
+    },
+    "/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/Microsoft.ContainerService/managedClusters/{resourceName}/agentPools/{agentPoolName}/upgradeNodeImageVersion": {
+      "post": {
+        "tags": [
+          "AgentPools"
+        ],
+        "operationId": "ManagedClusters_UpgradeNodeImageVersion",
+        "summary": "Upgrade node image version of an agent pool to the latest.",
+        "description": "Upgrade node image version of an agent pool to the latest.",
+        "parameters": [
+          {
+            "$ref": "#/parameters/ApiVersionParameter"
+          },
+          {
+            "$ref": "#/parameters/SubscriptionIdParameter"
+          },
+          {
+            "$ref": "#/parameters/ResourceGroupNameParameter"
+          },
+          {
+            "$ref": "#/parameters/ResourceNameParameter"
+          },
+          {
+            "name": "agentPoolName",
+            "in": "path",
+            "required": true,
+            "type": "string",
+            "description": "The name of the agent pool."
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "OK"
+          },
+          "202": {
+            "description": "Accepted",
+            "schema": {
+              "$ref": "#/definitions/AgentPool"
+            }
+          },
+          "default": {
+            "description": "Error response describing why the operation failed.",
+            "schema": {
+              "$ref": "#/definitions/CloudError"
+            }
+          }
+        },
+        "x-ms-long-running-operation": true,
+        "x-ms-examples": {
+          "Upgrade Agent Pool Node Image Version": {
+            "$ref": "./examples/AgentPoolsUpgradeNodeImageVersion.json"
+          }
+        }
+      }
     }
   },
   "definitions": {
@@ -1691,6 +1745,7 @@
           "description": "Version of orchestrator specified when creating the managed cluster."
         },
         "nodeImageVersion": {
+          "readOnly": true,
           "type": "string",
           "description": "Version of node image"
         },