diff --git a/src/Observability/Hosting/Extensions/TurnContextExtensions.cs b/src/Observability/Hosting/Extensions/TurnContextExtensions.cs
index 5ea8f8bc..f187824c 100644
--- a/src/Observability/Hosting/Extensions/TurnContextExtensions.cs
+++ b/src/Observability/Hosting/Extensions/TurnContextExtensions.cs
@@ -20,8 +20,9 @@ public static class TurnContextExtensions
         /// </summary>
         public static IEnumerable<KeyValuePair<string, object?>> GetCallerBaggagePairs(this ITurnContext turnContext)
         {
-            yield return new KeyValuePair<string, object?>(OpenTelemetryConstants.UserIdKey, turnContext.Activity?.From?.AadObjectId);
-            yield return new KeyValuePair<string, object?>(OpenTelemetryConstants.UserNameKey, turnContext.Activity?.From?.Name);
+            var from = turnContext.Activity?.From;
+            yield return new KeyValuePair<string, object?>(OpenTelemetryConstants.UserIdKey, from?.AadObjectId ?? from?.AgenticUserId ?? from?.Id);
+            yield return new KeyValuePair<string, object?>(OpenTelemetryConstants.UserNameKey, from?.Name);
         }
 
         /// <summary>
diff --git a/src/Tests/Microsoft.Agents.A365.Observability.Hosting.Tests/Middleware/BaggageTurnMiddlewareTests.cs b/src/Tests/Microsoft.Agents.A365.Observability.Hosting.Tests/Middleware/BaggageTurnMiddlewareTests.cs
index e5cde121..c090c241 100644
--- a/src/Tests/Microsoft.Agents.A365.Observability.Hosting.Tests/Middleware/BaggageTurnMiddlewareTests.cs
+++ b/src/Tests/Microsoft.Agents.A365.Observability.Hosting.Tests/Middleware/BaggageTurnMiddlewareTests.cs
@@ -107,9 +107,114 @@ public async Task OnTurnAsync_RestoresBaggageAfterNext()
         baggageAfterMiddleware.Should().Be(baggageBeforeMiddleware);
     }
 
+    [TestMethod]
+    public async Task OnTurnAsync_UserId_FallsBackToFromId_WhenAadObjectIdIsNull()
+    {
+        // Arrange — simulates email/Word/SPO channel where AadObjectId is null
+        var middleware = new BaggageTurnMiddleware();
+        var turnContext = CreateTurnContext(
+            channelName: "outlook",
+            fromId: "lukemoenning@microsoft.com",
+            fromAadObjectId: null);
+
+        string? capturedUserId = null;
+
+        NextDelegate next = (ct) =>
+        {
+            capturedUserId = Baggage.Current.GetBaggage(OpenTelemetryConstants.UserIdKey);
+            return Task.CompletedTask;
+        };
+
+        // Act
+        await middleware.OnTurnAsync(turnContext, next);
+
+        // Assert
+        capturedUserId.Should().Be("lukemoenning@microsoft.com");
+    }
+
+    [TestMethod]
+    public async Task OnTurnAsync_UserId_FallsBackToAgenticUserId_WhenAadObjectIdIsNull()
+    {
+        // Arrange — simulates A2A call where AadObjectId is null but AgenticUserId is set
+        var middleware = new BaggageTurnMiddleware();
+        var turnContext = CreateTurnContext(
+            fromId: "29:1sH5NArUwkWAX",
+            fromAadObjectId: null,
+            fromAgenticUserId: "agent@contoso.onmicrosoft.com");
+
+        string? capturedUserId = null;
+
+        NextDelegate next = (ct) =>
+        {
+            capturedUserId = Baggage.Current.GetBaggage(OpenTelemetryConstants.UserIdKey);
+            return Task.CompletedTask;
+        };
+
+        // Act
+        await middleware.OnTurnAsync(turnContext, next);
+
+        // Assert
+        capturedUserId.Should().Be("agent@contoso.onmicrosoft.com");
+    }
+
+    [TestMethod]
+    public async Task OnTurnAsync_UserId_PrefersAadObjectId_WhenBothAadAndAgenticUserIdSet()
+    {
+        // Arrange — both AadObjectId and AgenticUserId are populated; AadObjectId should win
+        var middleware = new BaggageTurnMiddleware();
+        var turnContext = CreateTurnContext(
+            channelName: "msteams",
+            fromId: "8:orgid:17649762-cd35-4a35-95ab-75eeb3017308",
+            fromAadObjectId: "aad-object-id-123",
+            fromAgenticUserId: "agent@contoso.onmicrosoft.com");
+
+        string? capturedUserId = null;
+
+        NextDelegate next = (ct) =>
+        {
+            capturedUserId = Baggage.Current.GetBaggage(OpenTelemetryConstants.UserIdKey);
+            return Task.CompletedTask;
+        };
+
+        // Act
+        await middleware.OnTurnAsync(turnContext, next);
+
+        // Assert
+        capturedUserId.Should().Be("aad-object-id-123");
+    }
+
+    [TestMethod]
+    public async Task OnTurnAsync_UserId_FallsBackToGuidAgenticUserId()
+    {
+        // Arrange — A2A where AgenticUserId is a GUID, not an email
+        var middleware = new BaggageTurnMiddleware();
+        var turnContext = CreateTurnContext(
+            fromId: "29:1sH5NArUwkWAX",
+            fromAadObjectId: null,
+            fromAgenticUserId: "bef730f4-d6f5-4ffb-b759-26ffa449ed7e");
+
+        string? capturedUserId = null;
+
+        NextDelegate next = (ct) =>
+        {
+            capturedUserId = Baggage.Current.GetBaggage(OpenTelemetryConstants.UserIdKey);
+            return Task.CompletedTask;
+        };
+
+        // Act
+        await middleware.OnTurnAsync(turnContext, next);
+
+        // Assert
+        capturedUserId.Should().Be("bef730f4-d6f5-4ffb-b759-26ffa449ed7e");
+    }
+
     private static ITurnContext CreateTurnContext(
         string activityType = "message",
-        string? activityName = null)
+        string? activityName = null,
+        string? fromId = "caller-id",
+        string? fromAadObjectId = "caller-aad",
+        string? fromAgenticUserId = null,
+        string channelName = "msteams")
     {
         var mockActivity = new Mock<IActivity>();
         mockActivity.Setup(a => a.Type).Returns(activityType);
@@ -120,9 +225,10 @@ private static ITurnContext CreateTurnContext(
         mockActivity.Setup(a => a.Text).Returns("Hello");
         mockActivity.Setup(a => a.From).Returns(new ChannelAccount
         {
-            Id = "caller-id",
+            Id = fromId,
             Name = "Caller",
-            AadObjectId = "caller-aad",
+            AadObjectId = fromAadObjectId,
+            AgenticUserId = fromAgenticUserId,
         });
         mockActivity.Setup(a => a.Recipient).Returns(new ChannelAccount
         {
@@ -133,7 +239,7 @@ private static ITurnContext CreateTurnContext(
         });
         mockActivity.Setup(a => a.Conversation).Returns(new ConversationAccount { Id = "conv-id" });
         mockActivity.Setup(a => a.ServiceUrl).Returns("https://example.com");
-        mockActivity.Setup(a => a.ChannelId).Returns(new ChannelId("test-channel"));
+        mockActivity.Setup(a => a.ChannelId).Returns(new ChannelId(channelName));
 
         var mockTurnContext = new Mock<ITurnContext>();
         mockTurnContext.Setup(tc => tc.Activity).Returns(mockActivity.Object);