diff --git a/specification/monitor/resource-manager/Microsoft.Insights/stable/2018-03-01/metricAlert_API.json b/specification/monitor/resource-manager/Microsoft.Insights/stable/2018-03-01/metricAlert_API.json
index 79be5f2a8c27..144a57d9ca92 100644
--- a/specification/monitor/resource-manager/Microsoft.Insights/stable/2018-03-01/metricAlert_API.json
+++ b/specification/monitor/resource-manager/Microsoft.Insights/stable/2018-03-01/metricAlert_API.json
@@ -543,6 +543,70 @@
       },
       "description": "An alert rule."
     },
+    "MetricAlertPropertiesPatch": {
+      "properties": {
+        "description": {
+          "type": "string",
+          "description": "the description of the metric alert that will be included in the alert email."
+        },
+        "severity": {
+          "type": "integer",
+          "format": "int32",
+          "description": "Alert severity {0, 1, 2, 3, 4}"
+        },
+        "enabled": {
+          "type": "boolean",
+          "description": "the flag that indicates whether the metric alert is enabled."
+        },
+        "scopes": {
+          "type": "array",
+          "items": {
+            "type": "string"
+          },
+          "description": "the list of resource id's that this metric alert is scoped to."
+        },
+        "evaluationFrequency": {
+          "type": "string",
+          "format": "duration",
+          "description": "how often the metric alert is evaluated represented in ISO 8601 duration format."
+        },
+        "windowSize": {
+          "type": "string",
+          "format": "duration",
+          "description": "the period of time (in ISO 8601 duration format) that is used to monitor alert activity based on the threshold."
+        },
+        "targetResourceType": {
+          "type": "string",
+          "description": "the resource type of the target resource(s) on which the alert is created/updated. Mandatory for MultipleResourceMultipleMetricCriteria."
+        },
+        "targetResourceRegion": {
+          "type": "string",
+          "description": "the region of the target resource(s) on which the alert is created/updated. Mandatory for MultipleResourceMultipleMetricCriteria."
+        },
+        "criteria": {
+          "$ref": "#/definitions/MetricAlertCriteria",
+          "description": "defines the specific alert criteria information."
+        },
+        "autoMitigate": {
+          "type": "boolean",
+          "description": "the flag that indicates whether the alert should be auto resolved or not. The default is true."
+        },
+        "actions": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/MetricAlertAction"
+          },
+          "description": "the array of actions that are performed when the alert rule becomes active, and when an alert condition is resolved."
+        },
+        "lastUpdatedTime": {
+          "readOnly": true,
+          "type": "string",
+          "format": "date-time",
+          "description": "Last time the rule was updated in ISO8601 format."
+        }
+      },
+      "description": "An alert rule properties for patch."
+    },
     "MetricAlertResource": {
       "type": "object",
       "allOf": [
@@ -572,7 +636,7 @@
         },
         "properties": {
           "x-ms-client-flatten": true,
-          "$ref": "#/definitions/MetricAlertProperties",
+          "$ref": "#/definitions/MetricAlertPropertiesPatch",
           "description": "The alert rule properties of the resource."
         }
       },