diff --git a/src/Agent.Listener/Agent.cs b/src/Agent.Listener/Agent.cs
index 34bb691944..bc10f46e44 100644
--- a/src/Agent.Listener/Agent.cs
+++ b/src/Agent.Listener/Agent.cs
@@ -327,7 +327,12 @@ private async Task<int> RunAsync(AgentSettings settings, bool runOnce = false)
             {
                 Trace.Info(nameof(RunAsync));
                 _listener = HostContext.GetService<IMessageListener>();
-                if (!await _listener.CreateSessionAsync(HostContext.AgentShutdownToken))
+                Constants.Agent.CreateSessionResult createSessionResult = await _listener.CreateSessionAsync(HostContext.AgentShutdownToken);
+                if (createSessionResult == Constants.Agent.CreateSessionResult.SessionConflict)
+                {
+                    return Constants.Agent.ReturnCode.SessionConflict;
+                }
+                else if (createSessionResult == Constants.Agent.CreateSessionResult.Failure)
                 {
                     return Constants.Agent.ReturnCode.TerminatedError;
                 }
diff --git a/src/Agent.Listener/MessageListener.cs b/src/Agent.Listener/MessageListener.cs
index eebca9d1f7..2b4dbfce0e 100644
--- a/src/Agent.Listener/MessageListener.cs
+++ b/src/Agent.Listener/MessageListener.cs
@@ -24,7 +24,7 @@ namespace Microsoft.VisualStudio.Services.Agent.Listener
     [ServiceLocator(Default = typeof(MessageListener))]
     public interface IMessageListener : IAgentService
     {
-        Task<Boolean> CreateSessionAsync(CancellationToken token);
+        Task<Constants.Agent.CreateSessionResult> CreateSessionAsync(CancellationToken token);
         Task DeleteSessionAsync();
         Task<TaskAgentMessage> GetNextMessageAsync(CancellationToken token);
         Task KeepAlive(CancellationToken token);
@@ -52,7 +52,7 @@ public override void Initialize(IHostContext hostContext)
             _agentServer = HostContext.GetService<IAgentServer>();
         }
 
-        public async Task<Boolean> CreateSessionAsync(CancellationToken token)
+        public async Task<Constants.Agent.CreateSessionResult> CreateSessionAsync(CancellationToken token)
         {
             Trace.Entering();
 
@@ -108,7 +108,7 @@ public async Task<Boolean> CreateSessionAsync(CancellationToken token)
                         encounteringError = false;
                     }
 
-                    return true;
+                    return Constants.Agent.CreateSessionResult.Success;
                 }
                 catch (OperationCanceledException) when (token.IsCancellationRequested)
                 {
@@ -133,7 +133,11 @@ public async Task<Boolean> CreateSessionAsync(CancellationToken token)
                     if (!IsSessionCreationExceptionRetriable(ex))
                     {
                         _term.WriteError(StringUtil.Loc("SessionCreateFailed", ex.Message));
-                        return false;
+                        if (ex is TaskAgentSessionConflictException)
+                        {
+                            return Constants.Agent.CreateSessionResult.SessionConflict;
+                        }
+                        return Constants.Agent.CreateSessionResult.Failure;
                     }
 
                     if (!encounteringError) //print the message only on the first error
@@ -211,7 +215,7 @@ public async Task<TaskAgentMessage> GetNextMessageAsync(CancellationToken token)
                     Trace.Error(ex);
 
                     // don't retry if SkipSessionRecover = true, DT service will delete agent session to stop agent from taking more jobs.
-                    if (ex is TaskAgentSessionExpiredException && !_settings.SkipSessionRecover && await CreateSessionAsync(token))
+                    if (ex is TaskAgentSessionExpiredException && !_settings.SkipSessionRecover && (await CreateSessionAsync(token) == Constants.Agent.CreateSessionResult.Success))
                     {
                         Trace.Info($"{nameof(TaskAgentSessionExpiredException)} received, recovered by recreate session.");
                     }
diff --git a/src/Microsoft.VisualStudio.Services.Agent/Constants.cs b/src/Microsoft.VisualStudio.Services.Agent/Constants.cs
index 2b0f630ae8..143ecd8e4f 100644
--- a/src/Microsoft.VisualStudio.Services.Agent/Constants.cs
+++ b/src/Microsoft.VisualStudio.Services.Agent/Constants.cs
@@ -202,6 +202,13 @@ public static class Flags
                 }
             }
 
+            public enum CreateSessionResult
+            {
+                Success,
+                Failure,
+                SessionConflict
+            }
+
             public static class ReturnCode
             {
                 public const int Success = 0;
@@ -209,6 +216,7 @@ public static class ReturnCode
                 public const int RetryableError = 2;
                 public const int AgentUpdating = 3;
                 public const int RunOnceAgentUpdating = 4;
+                public const int SessionConflict = 5;
             }
 
             public static class AgentConfigurationProvider
diff --git a/src/Test/L0/Listener/AgentL0.cs b/src/Test/L0/Listener/AgentL0.cs
index 14250ab78d..a74c710fdf 100644
--- a/src/Test/L0/Listener/AgentL0.cs
+++ b/src/Test/L0/Listener/AgentL0.cs
@@ -107,7 +107,7 @@ public async void TestRunAsync()
                 _configurationManager.Setup(x => x.IsConfigured())
                     .Returns(true);
                 _messageListener.Setup(x => x.CreateSessionAsync(It.IsAny<CancellationToken>()))
-                    .Returns(Task.FromResult<bool>(true));
+                    .Returns(Task.FromResult<Constants.Agent.CreateSessionResult>(Constants.Agent.ReturnCode.Success));
                 _messageListener.Setup(x => x.GetNextMessageAsync(It.IsAny<CancellationToken>()))
                     .Returns(async () =>
                         {
@@ -208,7 +208,7 @@ public async void TestExecuteCommandForRunAsService(string[] args, bool configur
                 _configStore.Setup(x => x.IsServiceConfigured()).Returns(configureAsService);
 
                 _messageListener.Setup(x => x.CreateSessionAsync(It.IsAny<CancellationToken>()))
-                    .Returns(Task.FromResult(false));
+                     .Returns(Task.FromResult<Constants.Agent.CreateSessionResult>(Constants.Agent.CreateSessionResult.Failure));
 
                 agent.Initialize(hc);
                 await agent.ExecuteCommand(command);
@@ -245,7 +245,7 @@ public async void TestMachineProvisionerCLI()
                     .Returns(false);
 
                 _messageListener.Setup(x => x.CreateSessionAsync(It.IsAny<CancellationToken>()))
-                    .Returns(Task.FromResult(false));
+                    .Returns(Task.FromResult<Constants.Agent.CreateSessionResult>(Constants.Agent.CreateSessionResult.Failure));
 
                 agent.Initialize(hc);
                 await agent.ExecuteCommand(command);
@@ -282,7 +282,7 @@ public async void TestMachineProvisionerCLICompat()
                     .Returns(false);
 
                 _messageListener.Setup(x => x.CreateSessionAsync(It.IsAny<CancellationToken>()))
-                    .Returns(Task.FromResult(false));
+                    .Returns(Task.FromResult<Constants.Agent.CreateSessionResult>(Constants.Agent.CreateSessionResult.Failure));
 
                 agent.Initialize(hc);
                 await agent.ExecuteCommand(command);
@@ -330,7 +330,7 @@ public async void TestRunOnce()
                 _configurationManager.Setup(x => x.IsConfigured())
                     .Returns(true);
                 _messageListener.Setup(x => x.CreateSessionAsync(It.IsAny<CancellationToken>()))
-                    .Returns(Task.FromResult<bool>(true));
+                    .Returns(Task.FromResult<Constants.Agent.CreateSessionResult>(Constants.Agent.CreateSessionResult.Success));
                 _messageListener.Setup(x => x.GetNextMessageAsync(It.IsAny<CancellationToken>()))
                     .Returns(async () =>
                         {
@@ -435,7 +435,7 @@ public async void TestRunOnceOnlyTakeOneJobMessage()
                 _configurationManager.Setup(x => x.IsConfigured())
                     .Returns(true);
                 _messageListener.Setup(x => x.CreateSessionAsync(It.IsAny<CancellationToken>()))
-                    .Returns(Task.FromResult<bool>(true));
+                    .Returns(Task.FromResult<Constants.Agent.CreateSessionResult>(Constants.Agent.CreateSessionResult.Success));
                 _messageListener.Setup(x => x.GetNextMessageAsync(It.IsAny<CancellationToken>()))
                     .Returns(async () =>
                         {
@@ -537,7 +537,7 @@ public async void TestRunOnceHandleUpdateMessage()
                 _configurationManager.Setup(x => x.IsConfigured())
                     .Returns(true);
                 _messageListener.Setup(x => x.CreateSessionAsync(It.IsAny<CancellationToken>()))
-                    .Returns(Task.FromResult<bool>(true));
+                    .Returns(Task.FromResult<Constants.Agent.CreateSessionResult>(Constants.Agent.CreateSessionResult.Success));
                 _messageListener.Setup(x => x.GetNextMessageAsync(It.IsAny<CancellationToken>()))
                     .Returns(async () =>
                         {
@@ -766,7 +766,7 @@ public async void TestMetadataUpdate()
                 _configurationManager.Setup(x => x.IsConfigured())
                     .Returns(true);
                 _messageListener.Setup(x => x.CreateSessionAsync(It.IsAny<CancellationToken>()))
-                    .Returns(Task.FromResult<bool>(true));
+                    .Returns(Task.FromResult<Constants.Agent.CreateSessionResult>(Constants.Agent.CreateSessionResult.Success));
                 _messageListener.Setup(x => x.GetNextMessageAsync(It.IsAny<CancellationToken>()))
                     .Returns(async () =>
                         {
diff --git a/src/Test/L0/Listener/MessageListenerL0.cs b/src/Test/L0/Listener/MessageListenerL0.cs
index 45a24d7b7e..1674f268d9 100644
--- a/src/Test/L0/Listener/MessageListenerL0.cs
+++ b/src/Test/L0/Listener/MessageListenerL0.cs
@@ -88,11 +88,11 @@ public async void CreatesSession()
                 MessageListener listener = new MessageListener();
                 listener.Initialize(tc);
 
-                bool result = await listener.CreateSessionAsync(tokenSource.Token);
+                Constants.Agent.CreateSessionResult result = await listener.CreateSessionAsync(tokenSource.Token);
                 trace.Info("result: {0}", result);
 
                 // Assert.
-                Assert.True(result);
+                Assert.Equal(Constants.Agent.CreateSessionResult.Success, result);
                 _agentServer
                     .Verify(x => x.CreateAgentSessionAsync(
                         _settings.PoolId,
@@ -132,8 +132,8 @@ public async void DeleteSession()
                 MessageListener listener = new MessageListener();
                 listener.Initialize(tc);
 
-                bool result = await listener.CreateSessionAsync(tokenSource.Token);
-                Assert.True(result);
+                Constants.Agent.CreateSessionResult result = await listener.CreateSessionAsync(tokenSource.Token);
+                Assert.Equal(Constants.Agent.CreateSessionResult.Success, result);
 
                 _agentServer
                     .Setup(x => x.DeleteAgentSessionAsync(
@@ -179,8 +179,8 @@ public async void GetNextMessage()
                 MessageListener listener = new MessageListener();
                 listener.Initialize(tc);
 
-                bool result = await listener.CreateSessionAsync(tokenSource.Token);
-                Assert.True(result);
+                Constants.Agent.CreateSessionResult result = await listener.CreateSessionAsync(tokenSource.Token);
+                Assert.Equal(Constants.Agent.CreateSessionResult.Success, result);
 
                 var arMessages = new TaskAgentMessage[]
                 {