diff --git a/sdk/eventgrid/Azure.Messaging.EventGrid/src/Generated/EventGridModelFactory.cs b/sdk/eventgrid/Azure.Messaging.EventGrid/src/Generated/EventGridModelFactory.cs
index 4bb5a0826301..6312ed484f9e 100644
--- a/sdk/eventgrid/Azure.Messaging.EventGrid/src/Generated/EventGridModelFactory.cs
+++ b/sdk/eventgrid/Azure.Messaging.EventGrid/src/Generated/EventGridModelFactory.cs
@@ -1220,14 +1220,12 @@ public static WebAppServicePlanUpdatedEventDataSku WebAppServicePlanUpdatedEvent
             return new WebAppServicePlanUpdatedEventDataSku(name, tier, size, family, capacity);
         }
 
-        /// <summary> Initializes a new instance of AcsChatEventBaseProperties. </summary>
-        /// <param name="recipientCommunicationIdentifier"> The communication identifier of the target user. </param>
-        /// <param name="transactionId"> The transaction id will be used as co-relation vector. </param>
-        /// <param name="threadId"> The chat thread id. </param>
-        /// <returns> A new <see cref="SystemEvents.AcsChatEventBaseProperties"/> instance for mocking. </returns>
-        public static AcsChatEventBaseProperties AcsChatEventBaseProperties(CommunicationIdentifierModel recipientCommunicationIdentifier = null, string transactionId = null, string threadId = null)
+        /// <summary> Initializes a new instance of AcsUserDisconnectedEventData. </summary>
+        /// <param name="userCommunicationIdentifier"> The communication identifier of the user who was disconnected. </param>
+        /// <returns> A new <see cref="SystemEvents.AcsUserDisconnectedEventData"/> instance for mocking. </returns>
+        public static AcsUserDisconnectedEventData AcsUserDisconnectedEventData(CommunicationIdentifierModel userCommunicationIdentifier = null)
         {
-            return new AcsChatEventBaseProperties(recipientCommunicationIdentifier, transactionId, threadId);
+            return new AcsUserDisconnectedEventData(userCommunicationIdentifier);
         }
 
         /// <summary> Initializes a new instance of CommunicationIdentifierModel. </summary>
@@ -1267,6 +1265,16 @@ public static MicrosoftTeamsUserIdentifierModel MicrosoftTeamsUserIdentifierMode
             return new MicrosoftTeamsUserIdentifierModel(userId, isAnonymous, cloud);
         }
 
+        /// <summary> Initializes a new instance of AcsChatEventBaseProperties. </summary>
+        /// <param name="recipientCommunicationIdentifier"> The communication identifier of the target user. </param>
+        /// <param name="transactionId"> The transaction id will be used as co-relation vector. </param>
+        /// <param name="threadId"> The chat thread id. </param>
+        /// <returns> A new <see cref="SystemEvents.AcsChatEventBaseProperties"/> instance for mocking. </returns>
+        public static AcsChatEventBaseProperties AcsChatEventBaseProperties(CommunicationIdentifierModel recipientCommunicationIdentifier = null, string transactionId = null, string threadId = null)
+        {
+            return new AcsChatEventBaseProperties(recipientCommunicationIdentifier, transactionId, threadId);
+        }
+
         /// <summary> Initializes a new instance of AcsChatMessageEventBaseProperties. </summary>
         /// <param name="recipientCommunicationIdentifier"> The communication identifier of the target user. </param>
         /// <param name="transactionId"> The transaction id will be used as co-relation vector. </param>
diff --git a/sdk/eventgrid/Azure.Messaging.EventGrid/src/Generated/Models/AcsUserDisconnectedEventData.Serialization.cs b/sdk/eventgrid/Azure.Messaging.EventGrid/src/Generated/Models/AcsUserDisconnectedEventData.Serialization.cs
new file mode 100644
index 000000000000..9d85fb13263f
--- /dev/null
+++ b/sdk/eventgrid/Azure.Messaging.EventGrid/src/Generated/Models/AcsUserDisconnectedEventData.Serialization.cs
@@ -0,0 +1,50 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+// <auto-generated/>
+
+#nullable disable
+
+using System;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using Azure.Core;
+
+namespace Azure.Messaging.EventGrid.SystemEvents
+{
+    [JsonConverter(typeof(AcsUserDisconnectedEventDataConverter))]
+    public partial class AcsUserDisconnectedEventData
+    {
+        internal static AcsUserDisconnectedEventData DeserializeAcsUserDisconnectedEventData(JsonElement element)
+        {
+            Optional<CommunicationIdentifierModel> userCommunicationIdentifier = default;
+            foreach (var property in element.EnumerateObject())
+            {
+                if (property.NameEquals("userCommunicationIdentifier"))
+                {
+                    if (property.Value.ValueKind == JsonValueKind.Null)
+                    {
+                        property.ThrowNonNullablePropertyIsNull();
+                        continue;
+                    }
+                    userCommunicationIdentifier = CommunicationIdentifierModel.DeserializeCommunicationIdentifierModel(property.Value);
+                    continue;
+                }
+            }
+            return new AcsUserDisconnectedEventData(userCommunicationIdentifier.Value);
+        }
+
+        internal partial class AcsUserDisconnectedEventDataConverter : JsonConverter<AcsUserDisconnectedEventData>
+        {
+            public override void Write(Utf8JsonWriter writer, AcsUserDisconnectedEventData model, JsonSerializerOptions options)
+            {
+                throw new NotImplementedException();
+            }
+            public override AcsUserDisconnectedEventData Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+            {
+                using var document = JsonDocument.ParseValue(ref reader);
+                return DeserializeAcsUserDisconnectedEventData(document.RootElement);
+            }
+        }
+    }
+}
diff --git a/sdk/eventgrid/Azure.Messaging.EventGrid/src/Generated/Models/AcsUserDisconnectedEventData.cs b/sdk/eventgrid/Azure.Messaging.EventGrid/src/Generated/Models/AcsUserDisconnectedEventData.cs
new file mode 100644
index 000000000000..9843a60936d4
--- /dev/null
+++ b/sdk/eventgrid/Azure.Messaging.EventGrid/src/Generated/Models/AcsUserDisconnectedEventData.cs
@@ -0,0 +1,28 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+// <auto-generated/>
+
+#nullable disable
+
+namespace Azure.Messaging.EventGrid.SystemEvents
+{
+    /// <summary> Schema of the Data property of an EventGridEvent for an Microsoft.Communication.UserDisconnected event. </summary>
+    public partial class AcsUserDisconnectedEventData
+    {
+        /// <summary> Initializes a new instance of AcsUserDisconnectedEventData. </summary>
+        internal AcsUserDisconnectedEventData()
+        {
+        }
+
+        /// <summary> Initializes a new instance of AcsUserDisconnectedEventData. </summary>
+        /// <param name="userCommunicationIdentifier"> The communication identifier of the user who was disconnected. </param>
+        internal AcsUserDisconnectedEventData(CommunicationIdentifierModel userCommunicationIdentifier)
+        {
+            UserCommunicationIdentifier = userCommunicationIdentifier;
+        }
+
+        /// <summary> The communication identifier of the user who was disconnected. </summary>
+        public CommunicationIdentifierModel UserCommunicationIdentifier { get; }
+    }
+}
diff --git a/sdk/eventgrid/Azure.Messaging.EventGrid/src/autorest.md b/sdk/eventgrid/Azure.Messaging.EventGrid/src/autorest.md
index 0f155aad0de4..8244287c114b 100644
--- a/sdk/eventgrid/Azure.Messaging.EventGrid/src/autorest.md
+++ b/sdk/eventgrid/Azure.Messaging.EventGrid/src/autorest.md
@@ -4,7 +4,7 @@ Run `dotnet build /t:GenerateCode` to generate code.
 
 ``` yaml
 title: EventGridClient
-require: https://github.com/Azure/azure-rest-api-specs/blob/504bc4ece6c4a1ad983f148237c71a3f72fc977f/specification/eventgrid/data-plane/readme.md
+require: https://github.com/Azure/azure-rest-api-specs/blob/6492c3a2b6d5217f5b83b18ad3fb6b625a79d5e8/specification/eventgrid/data-plane/readme.md
 ```
 
 ## Swagger workarounds