diff --git a/clients/client-xray/src/commands/GetTraceSummariesCommand.ts b/clients/client-xray/src/commands/GetTraceSummariesCommand.ts
index b4794435a50c..b612cb591763 100644
--- a/clients/client-xray/src/commands/GetTraceSummariesCommand.ts
+++ b/clients/client-xray/src/commands/GetTraceSummariesCommand.ts
@@ -77,6 +77,7 @@ export interface GetTraceSummariesCommandOutput extends GetTraceSummariesResult,
  * //   TraceSummaries: [ // TraceSummaryList
  * //     { // TraceSummary
  * //       Id: "STRING_VALUE",
+ * //       StartTime: new Date("TIMESTAMP"),
  * //       Duration: Number("double"),
  * //       ResponseTime: Number("double"),
  * //       HasFault: true || false,
diff --git a/clients/client-xray/src/models/models_0.ts b/clients/client-xray/src/models/models_0.ts
index 396f40c3203d..f599439a1bdc 100644
--- a/clients/client-xray/src/models/models_0.ts
+++ b/clients/client-xray/src/models/models_0.ts
@@ -2720,6 +2720,12 @@ export interface TraceSummary {
    */
   Id?: string;
 
+  /**
+   * @public
+   * <p>The start time of a trace, based on the earliest trace segment start time.</p>
+   */
+  StartTime?: Date;
+
   /**
    * @public
    * <p>The length of time in seconds between the start time of the root segment and the end
diff --git a/clients/client-xray/src/protocols/Aws_restJson1.ts b/clients/client-xray/src/protocols/Aws_restJson1.ts
index e2ad027e3ea6..4f635854e537 100644
--- a/clients/client-xray/src/protocols/Aws_restJson1.ts
+++ b/clients/client-xray/src/protocols/Aws_restJson1.ts
@@ -3477,6 +3477,7 @@ const de_TraceSummary = (output: any, context: __SerdeContext): TraceSummary =>
     ResponseTimeRootCauses: (_: any) => de_ResponseTimeRootCauses(_, context),
     Revision: __expectInt32,
     ServiceIds: _json,
+    StartTime: (_: any) => __expectNonNull(__parseEpochTimestamp(__expectNumber(_))),
     Users: _json,
   }) as any;
 };
diff --git a/codegen/sdk-codegen/aws-models/xray.json b/codegen/sdk-codegen/aws-models/xray.json
index 374939dd7ae0..a1299ba4d235 100644
--- a/codegen/sdk-codegen/aws-models/xray.json
+++ b/codegen/sdk-codegen/aws-models/xray.json
@@ -5716,6 +5716,12 @@
             "smithy.api#documentation": "<p>The unique identifier for the request that generated the trace's segments and\n      subsegments.</p>"
           }
         },
+        "StartTime": {
+          "target": "com.amazonaws.xray#Timestamp",
+          "traits": {
+            "smithy.api#documentation": "<p>The start time of a trace, based on the earliest trace segment start time.</p>"
+          }
+        },
         "Duration": {
           "target": "com.amazonaws.xray#NullableDouble",
           "traits": {
@@ -6165,4 +6171,4 @@
       }
     }
   }
-}
\ No newline at end of file
+}