diff --git a/sdks/python/apache_beam/pipeline.py b/sdks/python/apache_beam/pipeline.py
index 04ecbf161c75..1044c136671f 100644
--- a/sdks/python/apache_beam/pipeline.py
+++ b/sdks/python/apache_beam/pipeline.py
@@ -78,6 +78,9 @@
 from apache_beam.typehints import typehints
 from apache_beam.utils.annotations import deprecated
 
+if typing.TYPE_CHECKING:
+  from apache_beam.portability.api import beam_runner_api_pb2
+
 __all__ = ['Pipeline', 'PTransformOverride']
 
 
@@ -611,6 +614,7 @@ def visit_value(self, value, _):
   def to_runner_api(
       self, return_context=False, context=None, use_fake_coders=False,
       default_environment=None):
+    # type: (...) -> beam_runner_api_pb2.Pipeline
     """For internal use only; no backwards-compatibility guarantees."""
     from apache_beam.runners import pipeline_context
     from apache_beam.portability.api import beam_runner_api_pb2
diff --git a/sdks/python/apache_beam/runners/interactive/display/pipeline_graph.py b/sdks/python/apache_beam/runners/interactive/display/pipeline_graph.py
index 23605b535c33..d29c48059489 100644
--- a/sdks/python/apache_beam/runners/interactive/display/pipeline_graph.py
+++ b/sdks/python/apache_beam/runners/interactive/display/pipeline_graph.py
@@ -26,6 +26,7 @@
 
 import collections
 import threading
+import typing
 
 import pydot
 
@@ -37,9 +38,10 @@ class PipelineGraph(object):
   """Creates a DOT representation of the pipeline. Thread-safe."""
 
   def __init__(self,
-               pipeline,
+               pipeline,  # type: typing.Union[beam_runner_api_pb2.Pipeline, beam.Pipeline]
                default_vertex_attrs=None,
-               default_edge_attrs=None):
+               default_edge_attrs=None
+               ):
     """Constructor of PipelineGraph.
 
     Examples:
@@ -57,7 +59,7 @@ def __init__(self,
       default_edge_attrs: (Dict[str, str]) a dict of default edge attributes
     """
     self._lock = threading.Lock()
-    self._graph = None
+    self._graph = None  # type: pydot.Dot
 
     if isinstance(pipeline, beam_runner_api_pb2.Pipeline):
       self._pipeline_proto = pipeline
@@ -93,6 +95,7 @@ def __init__(self,
                           default_edge_attrs)
 
   def get_dot(self):
+    # type: () -> str
     return self._get_graph().to_string()
 
   def _top_level_transforms(self):
diff --git a/sdks/python/apache_beam/runners/interactive/display/pipeline_graph_renderer.py b/sdks/python/apache_beam/runners/interactive/display/pipeline_graph_renderer.py
index a216d195a1f1..d07f7c79dfaa 100644
--- a/sdks/python/apache_beam/runners/interactive/display/pipeline_graph_renderer.py
+++ b/sdks/python/apache_beam/runners/interactive/display/pipeline_graph_renderer.py
@@ -27,11 +27,15 @@
 import abc
 import os
 import subprocess
+import typing
 
 from future.utils import with_metaclass
 
 from apache_beam.utils.plugin import BeamPlugin
 
+if typing.TYPE_CHECKING:
+  from apache_beam.runners.interactive.display.pipeline_graph import PipelineGraph
+
 
 class PipelineGraphRenderer(with_metaclass(abc.ABCMeta, BeamPlugin)):
   """Abstract class for renderers, who decide how pipeline graphs are rendered.
@@ -40,12 +44,14 @@ class PipelineGraphRenderer(with_metaclass(abc.ABCMeta, BeamPlugin)):
   @classmethod
   @abc.abstractmethod
   def option(cls):
+    # type: () -> str
     """The corresponding rendering option for the renderer.
     """
     raise NotImplementedError
 
   @abc.abstractmethod
   def render_pipeline_graph(self, pipeline_graph):
+    # type: (PipelineGraph) -> str
     """Renders the pipeline graph in HTML-compatible format.
 
     Args:
@@ -63,9 +69,11 @@ class MuteRenderer(PipelineGraphRenderer):
 
   @classmethod
   def option(cls):
+    # type: () -> str
     return 'mute'
 
   def render_pipeline_graph(self, pipeline_graph):
+    # type: (PipelineGraph) -> str
     return ''
 
 
@@ -75,9 +83,11 @@ class TextRenderer(PipelineGraphRenderer):
 
   @classmethod
   def option(cls):
+    # type: () -> str
     return 'text'
 
   def render_pipeline_graph(self, pipeline_graph):
+    # type: (PipelineGraph) -> str
     return pipeline_graph.get_dot()
 
 
@@ -91,13 +101,16 @@ class PydotRenderer(PipelineGraphRenderer):
 
   @classmethod
   def option(cls):
+    # type: () -> str
     return 'graph'
 
   def render_pipeline_graph(self, pipeline_graph):
+    # type: (PipelineGraph) -> str
     return pipeline_graph._get_graph().create_svg()  # pylint: disable=protected-access
 
 
 def get_renderer(option=None):
+  # type: (typing.Optional[str]) -> typing.Type[PipelineGraphRenderer]
   """Get an instance of PipelineGraphRenderer given rendering option.
 
   Args:
diff --git a/sdks/python/apache_beam/runners/portability/portable_runner.py b/sdks/python/apache_beam/runners/portability/portable_runner.py
index 117477af93c6..511fe14e13ed 100644
--- a/sdks/python/apache_beam/runners/portability/portable_runner.py
+++ b/sdks/python/apache_beam/runners/portability/portable_runner.py
@@ -27,6 +27,7 @@
 import sys
 import threading
 import time
+import typing
 from concurrent import futures
 
 import grpc
@@ -52,6 +53,9 @@
 from apache_beam.runners.worker import sdk_worker
 from apache_beam.runners.worker import sdk_worker_main
 
+if typing.TYPE_CHECKING:
+  from apache_beam.pipeline import Pipeline
+
 __all__ = ['PortableRunner']
 
 MESSAGE_LOG_LEVELS = {
@@ -112,6 +116,7 @@ def default_docker_image():
 
   @staticmethod
   def _create_environment(options):
+    # type: (...) -> beam_runner_api_pb2.Environment
     portable_options = options.view_as(PortableOptions)
     environment_urn = common_urns.environments.DOCKER.urn
     if portable_options.environment_type == 'DOCKER':
@@ -166,6 +171,7 @@ def init_dockerized_job_server(self):
     self._job_endpoint = docker.start()
 
   def run_pipeline(self, pipeline, options):
+    # type: (Pipeline, typing.Any) -> PipelineResult
     portable_options = options.view_as(PortableOptions)
     job_endpoint = portable_options.job_endpoint
 
diff --git a/sdks/python/apache_beam/runners/portability/portable_stager.py b/sdks/python/apache_beam/runners/portability/portable_stager.py
index 09ff18fd4565..1fbe8f370fc5 100644
--- a/sdks/python/apache_beam/runners/portability/portable_stager.py
+++ b/sdks/python/apache_beam/runners/portability/portable_stager.py
@@ -22,6 +22,7 @@
 
 import hashlib
 import os
+import typing
 
 from apache_beam.portability.api import beam_artifact_api_pb2
 from apache_beam.portability.api import beam_artifact_api_pb2_grpc
@@ -54,9 +55,10 @@ def __init__(self, artifact_service_channel, staging_session_token):
     self._artifact_staging_stub = beam_artifact_api_pb2_grpc.\
         ArtifactStagingServiceStub(channel=artifact_service_channel)
     self._staging_session_token = staging_session_token
-    self._artifacts = []
+    self._artifacts = []  # type: typing.List[beam_artifact_api_pb2.ArtifactMetadata]
 
   def stage_artifact(self, local_path_to_artifact, artifact_name):
+    # type: (str, str) -> None
     """Stage a file to ArtifactStagingService.
 
     Args:
@@ -69,6 +71,7 @@ def stage_artifact(self, local_path_to_artifact, artifact_name):
           .format(local_path_to_artifact))
 
     def artifact_request_generator():
+      # type: () -> typing.Iterator[beam_artifact_api_pb2.PutArtifactRequest]
       artifact_metadata = beam_artifact_api_pb2.ArtifactMetadata(
           name=artifact_name,
           sha256=_get_file_hash(local_path_to_artifact),
diff --git a/sdks/python/apache_beam/runners/portability/stager.py b/sdks/python/apache_beam/runners/portability/stager.py
index 0448a255aea2..7de5c3b48355 100644
--- a/sdks/python/apache_beam/runners/portability/stager.py
+++ b/sdks/python/apache_beam/runners/portability/stager.py
@@ -52,6 +52,7 @@
 import shutil
 import sys
 import tempfile
+import typing
 
 import pkg_resources
 
@@ -107,10 +108,11 @@ def get_sdk_package_name():
 
   def stage_job_resources(self,
                           options,
-                          build_setup_args=None,
-                          temp_dir=None,
-                          populate_requirements_cache=None,
-                          staging_location=None):
+                          build_setup_args=None,  # type: typing.Optional[typing.List[str]]
+                          temp_dir=None,  # type: typing.Optional[str]
+                          populate_requirements_cache=None,  # type: typing.Optional[str]
+                          staging_location=None
+                          ):
     """For internal use only; no backwards-compatibility guarantees.
 
         Creates (if needed) and stages job resources to staging_location.
diff --git a/sdks/python/apache_beam/runners/worker/sdk_worker.py b/sdks/python/apache_beam/runners/worker/sdk_worker.py
index 0c522744de9c..077c34cea3e0 100644
--- a/sdks/python/apache_beam/runners/worker/sdk_worker.py
+++ b/sdks/python/apache_beam/runners/worker/sdk_worker.py
@@ -80,7 +80,7 @@ def __init__(
         data_channel_factory=self._data_channel_factory,
         fns=self._fns)
     # workers for process/finalize bundle.
-    self.workers = queue.Queue()
+    self.workers = queue.Queue()  # type: queue.Queue[SdkWorker]
     # one worker for progress/split request.
     self.progress_worker = SdkWorker(self._bundle_processor_cache,
                                      profiler_factory=self._profiler_factory)
@@ -330,7 +330,10 @@ def shutdown(self):
 
 class SdkWorker(object):
 
-  def __init__(self, bundle_processor_cache, profiler_factory=None):
+  def __init__(self,
+               bundle_processor_cache,  # type: BundleProcessorCache
+               profiler_factory=None
+               ):
     self.bundle_processor_cache = bundle_processor_cache
     self.profiler_factory = profiler_factory
 
@@ -526,6 +529,7 @@ class GrpcStateHandler(object):
   _DONE = object()
 
   def __init__(self, state_stub):
+    # type: (beam_fn_api_pb2_grpc.BeamFnStateStub) -> None
     self._lock = threading.Lock()
     self._state_stub = state_stub
     self._requests = queue.Queue()