diff --git a/src/Microsoft.OpenTelemetry/Agent365/Hosting/Extensions/TurnContextExtensions.cs b/src/Microsoft.OpenTelemetry/Agent365/Hosting/Extensions/TurnContextExtensions.cs
index 5ea8f8b..f187824 100644
--- a/src/Microsoft.OpenTelemetry/Agent365/Hosting/Extensions/TurnContextExtensions.cs
+++ b/src/Microsoft.OpenTelemetry/Agent365/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/test/Microsoft.OpenTelemetry.Agent365.Tests/Hosting/Extensions/TurnContextExtensionsTests.cs b/test/Microsoft.OpenTelemetry.Agent365.Tests/Hosting/Extensions/TurnContextExtensionsTests.cs
new file mode 100644
index 0000000..f10f6d5
--- /dev/null
+++ b/test/Microsoft.OpenTelemetry.Agent365.Tests/Hosting/Extensions/TurnContextExtensionsTests.cs
@@ -0,0 +1,108 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+using FluentAssertions;
+using Microsoft.Agents.A365.Observability.Hosting.Extensions;
+using Microsoft.Agents.A365.Observability.Runtime.Tracing.Scopes;
+using Microsoft.Agents.Builder;
+using Microsoft.Agents.Core.Models;
+using Moq;
+
+namespace Microsoft.Agents.A365.Observability.Hosting.Tests.Extensions;
+
+[TestClass]
+public class TurnContextExtensionsTests
+{
+    [TestMethod]
+    public void GetCallerBaggagePairs_AadObjectIdSet_ReturnsAadObjectId()
+    {
+        // Arrange – Teams-like channel where AadObjectId, AgenticUserId, and From.Id are all set
+        var turnContext = CreateTurnContext(
+            fromId: "from-id",
+            aadObjectId: "aad-object-id",
+            agenticUserId: "agentic-user-id");
+
+        // Act
+        var pairs = turnContext.GetCallerBaggagePairs().ToDictionary(p => p.Key, p => p.Value);
+
+        // Assert – AadObjectId takes precedence
+        pairs[OpenTelemetryConstants.UserIdKey].Should().Be("aad-object-id");
+    }
+
+    [TestMethod]
+    public void GetCallerBaggagePairs_NoAadObjectId_FallsBackToAgenticUserId()
+    {
+        // Arrange – A2A scenario where AadObjectId is null but AgenticUserId is set
+        var turnContext = CreateTurnContext(
+            fromId: "from-id",
+            aadObjectId: null,
+            agenticUserId: "agentic-user-id");
+
+        // Act
+        var pairs = turnContext.GetCallerBaggagePairs().ToDictionary(p => p.Key, p => p.Value);
+
+        // Assert – falls back to AgenticUserId
+        pairs[OpenTelemetryConstants.UserIdKey].Should().Be("agentic-user-id");
+    }
+
+    [TestMethod]
+    public void GetCallerBaggagePairs_NoAadObjectId_FallsBackToGuidAgenticUserId()
+    {
+        // Arrange – A2A scenario where AgenticUserId is a GUID
+        var turnContext = CreateTurnContext(
+            fromId: "29:1sH5NArUwkWAX",
+            aadObjectId: null,
+            agenticUserId: "bef730f4-d6f5-4ffb-b759-26ffa449ed7e");
+
+        // Act
+        var pairs = turnContext.GetCallerBaggagePairs().ToDictionary(p => p.Key, p => p.Value);
+
+        // Assert – falls back to AgenticUserId (GUID format)
+        pairs[OpenTelemetryConstants.UserIdKey].Should().Be("bef730f4-d6f5-4ffb-b759-26ffa449ed7e");
+    }
+
+    [TestMethod]
+    public void GetCallerBaggagePairs_NoAadObjectIdNoAgenticUserId_FallsBackToFromId()
+    {
+        // Arrange – non-Teams channel where only From.Id is available
+        var turnContext = CreateTurnContext(
+            fromId: "from-id",
+            aadObjectId: null,
+            agenticUserId: null);
+
+        // Act
+        var pairs = turnContext.GetCallerBaggagePairs().ToDictionary(p => p.Key, p => p.Value);
+
+        // Assert – falls back to From.Id
+        pairs[OpenTelemetryConstants.UserIdKey].Should().Be("from-id");
+    }
+
+    private static ITurnContext CreateTurnContext(
+        string? fromId = "caller-id",
+        string? aadObjectId = "caller-aad",
+        string? agenticUserId = null,
+        string? fromName = "Caller")
+    {
+        var from = new ChannelAccount
+        {
+            Id = fromId,
+            Name = fromName,
+            AadObjectId = aadObjectId,
+        };
+
+        // Set AgenticUserId
+        if (agenticUserId != null)
+        {
+            from.AgenticUserId = agenticUserId;
+        }
+
+        var mockActivity = new Mock<IActivity>();
+        mockActivity.Setup(a => a.Type).Returns("message");
+        mockActivity.Setup(a => a.From).Returns(from);
+
+        var mockTurnContext = new Mock<ITurnContext>();
+        mockTurnContext.Setup(tc => tc.Activity).Returns(mockActivity.Object);
+
+        return mockTurnContext.Object;
+    }
+}