diff --git a/src/google/adk/agents/base_agent.py b/src/google/adk/agents/base_agent.py
index dec85690b3..a73192f7b2 100644
--- a/src/google/adk/agents/base_agent.py
+++ b/src/google/adk/agents/base_agent.py
@@ -181,8 +181,12 @@ def _load_agent_state(
     """
     if ctx.agent_states is None or self.name not in ctx.agent_states:
       return None
-    else:
-      return state_type.model_validate(ctx.agent_states.get(self.name))
+
+    raw_state = ctx.agent_states.get(self.name)
+    if raw_state == {} and state_type is not BaseAgentState:
+      return None
+
+    return state_type.model_validate(raw_state)
 
   def _create_agent_state_event(
       self,
diff --git a/tests/unittests/agents/test_base_agent.py b/tests/unittests/agents/test_base_agent.py
index cd9e88f718..a879de385c 100644
--- a/tests/unittests/agents/test_base_agent.py
+++ b/tests/unittests/agents/test_base_agent.py
@@ -1020,6 +1020,26 @@ async def test_load_agent_state_with_resume():
   assert state == persisted_state
 
 
+@pytest.mark.asyncio
+async def test_load_agent_state_ignores_base_placeholder_for_custom_state():
+  agent = BaseAgent(name='test_agent')
+  session_service = InMemorySessionService()
+  session = await session_service.create_session(
+      app_name='test_app', user_id='test_user'
+  )
+  ctx = InvocationContext(
+      invocation_id='test_invocation',
+      agent=agent,
+      session=session,
+      session_service=session_service,
+      resumability_config=ResumabilityConfig(is_resumable=True),
+  )
+  ctx.agent_states[agent.name] = BaseAgentState().model_dump(mode='json')
+
+  state = agent._load_agent_state(ctx, _TestAgentState)
+  assert state is None
+
+
 @pytest.mark.asyncio
 async def test_create_agent_state_event():
   agent = BaseAgent(name='test_agent')
diff --git a/tests/unittests/agents/test_sequential_agent.py b/tests/unittests/agents/test_sequential_agent.py
index 85523d2dca..b40e2d139b 100644
--- a/tests/unittests/agents/test_sequential_agent.py
+++ b/tests/unittests/agents/test_sequential_agent.py
@@ -17,6 +17,7 @@
 from typing import AsyncGenerator
 
 from google.adk.agents.base_agent import BaseAgent
+from google.adk.agents.base_agent import BaseAgentState
 from google.adk.agents.invocation_context import InvocationContext
 from google.adk.agents.sequential_agent import SequentialAgent
 from google.adk.agents.sequential_agent import SequentialAgentState
@@ -180,6 +181,43 @@ async def test_resume_async(request: pytest.FixtureRequest):
   assert events[1].actions.end_of_agent
 
 
+@pytest.mark.asyncio
+async def test_resume_async_ignores_base_placeholder_state(
+    request: pytest.FixtureRequest,
+):
+  agent_1 = _TestingAgent(name=f'{request.function.__name__}_test_agent_1')
+  agent_2 = _TestingAgent(name=f'{request.function.__name__}_test_agent_2')
+  sequential_agent = SequentialAgent(
+      name=f'{request.function.__name__}_test_agent',
+      sub_agents=[
+          agent_1,
+          agent_2,
+      ],
+  )
+  parent_ctx = await _create_parent_invocation_context(
+      request.function.__name__, sequential_agent, resumable=True
+  )
+  parent_ctx.agent_states[sequential_agent.name] = BaseAgentState().model_dump(
+      mode='json'
+  )
+
+  events = [e async for e in sequential_agent.run_async(parent_ctx)]
+
+  assert len(events) == 5
+  assert events[0].author == sequential_agent.name
+  assert events[0].actions.agent_state == SequentialAgentState(
+      current_sub_agent=agent_1.name
+  ).model_dump(mode='json')
+  assert events[1].author == agent_1.name
+  assert events[2].author == sequential_agent.name
+  assert events[2].actions.agent_state == SequentialAgentState(
+      current_sub_agent=agent_2.name
+  ).model_dump(mode='json')
+  assert events[3].author == agent_2.name
+  assert events[4].author == sequential_agent.name
+  assert events[4].actions.end_of_agent
+
+
 @pytest.mark.asyncio
 async def test_run_live(request: pytest.FixtureRequest):
   agent_1 = _TestingAgent(name=f'{request.function.__name__}_test_agent_1')