diff --git a/litellm/proxy/_experimental/mcp_server/server.py b/litellm/proxy/_experimental/mcp_server/server.py
index 4cc7446fd32..41673c7283d 100644
--- a/litellm/proxy/_experimental/mcp_server/server.py
+++ b/litellm/proxy/_experimental/mcp_server/server.py
@@ -3178,6 +3178,7 @@ if MCP_AVAILABLE:
                     client_ip=_client_ip,
                     session_id=session_id if use_stateful else None,
                     touch_last_seen=(scope.get("method") or "").upper() != "DELETE",
+                    copy_existing_session_auth_context=is_initialize,
                 )
                 local_send = send
                 if use_stateful and is_initialize:
@@ -3409,6 +3410,7 @@ if MCP_AVAILABLE:
         client_ip: Optional[str] = None,
         session_id: Optional[str] = None,
         touch_last_seen: bool = True,
+        copy_existing_session_auth_context: bool = False,
     ) -> MCPAuthenticatedUser:
         auth_user = (
             _stateful_session_auth_contexts.get(session_id) if session_id else None
@@ -3416,6 +3418,16 @@ if MCP_AVAILABLE:
         if auth_user is not None and session_id is not None:
             if touch_last_seen:
                 _stateful_session_auth_context_last_seen[session_id] = time.monotonic()
+            if copy_existing_session_auth_context:
+                return set_auth_context(
+                    user_api_key_auth=user_api_key_auth,
+                    mcp_auth_header=mcp_auth_header,
+                    mcp_servers=mcp_servers,
+                    mcp_server_auth_headers=mcp_server_auth_headers,
+                    oauth2_headers=oauth2_headers,
+                    raw_headers=raw_headers,
+                    client_ip=client_ip,
+                )
             _update_auth_context(
                 auth_user=auth_user,
                 user_api_key_auth=user_api_key_auth,
diff --git a/tests/test_litellm/proxy/_experimental/mcp_server/test_mcp_server.py b/tests/test_litellm/proxy/_experimental/mcp_server/test_mcp_server.py
index cf6fdb04a23..f8fab3aff67 100644
--- a/tests/test_litellm/proxy/_experimental/mcp_server/test_mcp_server.py
+++ b/tests/test_litellm/proxy/_experimental/mcp_server/test_mcp_server.py
@@ -1655,6 +1655,15 @@ async def test_initialize_request_with_existing_session_tracks_new_session():
     new_session_id = "reinitialized-session"
     owner_auth = UserAPIKeyAuth(api_key="initialize-key", user_id="user-a")
     owner_fingerprint = mcp_server._owner_fingerprint_for(owner_auth)
+    existing_auth_user = mcp_server.MCPAuthenticatedUser(
+        user_api_key_auth=owner_auth,
+        mcp_auth_header="old-mcp-auth",
+        mcp_servers=["old-server"],
+        mcp_server_auth_headers={"old-server": {"Authorization": "Bearer old-key"}},
+        oauth2_headers={"Authorization": "Bearer old-oauth"},
+        raw_headers={"x-old-header": "old"},
+        client_ip="old-client-ip",
+    )
     initialize_body = b'{"jsonrpc":"2.0","id":1,"method":"initialize","params":{}}'
     scope = {
         "type": "http",
@@ -1694,6 +1703,14 @@ async def test_initialize_request_with_existing_session_tracks_new_session():
         )
         await mcp_server._purge_expired_stateful_session_auth_contexts(now=now)
         assert new_session_id in mcp_server._stateful_session_auth_contexts
+        assert (
+            mcp_server._stateful_session_auth_contexts[new_session_id]
+            is not existing_auth_user
+        )
+        assert (
+            mcp_server._stateful_session_auth_contexts[new_session_id].mcp_auth_header
+            == "new-mcp-auth"
+        )
 
     async def stateless_handle(s, r, se):
         raise AssertionError(
@@ -1702,7 +1719,7 @@ async def test_initialize_request_with_existing_session_tracks_new_session():
 
     try:
         mcp_server._stateful_session_auth_contexts[existing_session_id] = (
-            mcp_server.MCPAuthenticatedUser(user_api_key_auth=owner_auth)
+            existing_auth_user
         )
         mcp_server._stateful_session_auth_context_last_seen[existing_session_id] = 1.0
         mcp_server._stateful_session_owners[existing_session_id] = owner_fingerprint
@@ -1711,7 +1728,14 @@ async def test_initialize_request_with_existing_session_tracks_new_session():
             patch(
                 "litellm.proxy._experimental.mcp_server.server.extract_mcp_auth_context",
                 new_callable=AsyncMock,
-                return_value=(owner_auth, None, None, None, None, None),
+                return_value=(
+                    owner_auth,
+                    "new-mcp-auth",
+                    ["new-server"],
+                    {"new-server": {"Authorization": "Bearer new-key"}},
+                    {"Authorization": "Bearer new-oauth"},
+                    {"x-new-header": "new"},
+                ),
             ),
             patch(
                 "litellm.proxy._experimental.mcp_server.server._SESSION_MANAGERS_INITIALIZED",
@@ -1738,6 +1762,12 @@ async def test_initialize_request_with_existing_session_tracks_new_session():
         assert stateful_called
         assert new_session_id not in mcp_server._stateful_session_active_request_counts
         assert new_session_id in mcp_server._stateful_session_auth_contexts
+        assert (
+            mcp_server._stateful_session_auth_contexts[existing_session_id]
+            is existing_auth_user
+        )
+        assert existing_auth_user.mcp_auth_header == "old-mcp-auth"
+        assert existing_auth_user.mcp_servers == ["old-server"]
     finally:
         mcp_server._remove_stateful_session_tracking(existing_session_id)
         mcp_server._remove_stateful_session_tracking(new_session_id)