diff --git a/langfun/core/eval/v2/runners/ckpt_monitor.py b/langfun/core/eval/v2/runners/ckpt_monitor.py
index 174df2f3..fee1275d 100644
--- a/langfun/core/eval/v2/runners/ckpt_monitor.py
+++ b/langfun/core/eval/v2/runners/ckpt_monitor.py
@@ -110,6 +110,7 @@ def start(self):
       # This is not precise, but we at least notify example start.
       if not self.current_run.filter or self.current_run.filter(evaluation):
         self.on_experiment_start(evaluation)
+        self._set_prior_elapse_from_checkpoints(evaluation)
 
         # Signal the start of the examples if we are not monitoring in-progress
         # files.
@@ -353,6 +354,31 @@ def _mark_example_started(
     # HTML could show remotely in-progress examples.
     evaluation.state.update(example, in_progress=True)
 
+  def _set_prior_elapse_from_checkpoints(
+      self,
+      evaluation: evaluation_lib.Evaluation,
+  ) -> None:
+    output_dir = self.current_run.output_dir(evaluation)
+    ckpt_file_pattern = os.path.join(output_dir, self.checkpoint_pattern)
+    total_elapse = 0.0
+    for filepath in pg.io.glob(ckpt_file_pattern):
+      last_modified_time = pg.io.getmtime(filepath)
+      if last_modified_time >= self.ckpt_start_time:
+        continue
+      try:
+        loaded_examples = evaluation.state.load(
+            filepath,
+            example_input_by_id=evaluation.example_input_by_id,
+            load_example_metadata=False,
+        )
+        for example in loaded_examples:
+          if example.start_time is not None and example.end_time is not None:
+            total_elapse += example.end_time - example.start_time
+      except Exception:  # pylint: disable=broad-except
+        pass
+    if total_elapse > 0:
+      evaluation.progress.add_prior_elapse(total_elapse)
+
   def _run(self, evaluations: list[evaluation_lib.Evaluation]):
     raise NotImplementedError('Not needed in checkpoint monitor.')
 
diff --git a/langfun/core/eval/v2/runners/ckpt_monitor_test.py b/langfun/core/eval/v2/runners/ckpt_monitor_test.py
index 5e1e29e3..cb906795 100644
--- a/langfun/core/eval/v2/runners/ckpt_monitor_test.py
+++ b/langfun/core/eval/v2/runners/ckpt_monitor_test.py
@@ -208,6 +208,33 @@ def on_experiment_complete(
           ckpt_start_time=ckpt_start_time,
       ).run()
 
+  def test_prior_elapse_accumulated_from_preexisting_checkpoints(self):
+    exp = eval_test_helper.test_evaluation()
+    root_dir = os.path.join(self.test_dir, 'test_prior_elapse')
+    run = exp.run(
+        root_dir,
+        runner='sequential',
+        progress_tracker=None,
+        plugins=[
+            checkpointing.PerExampleCheckpointer(
+                checkpoint_filename='checkpoint.jsonl'
+            )
+        ],
+        use_cache='no',
+    )
+
+    ckpt_start_time = time.time()
+    monitor = ckpt_monitor.CheckpointMonitor(
+        run,
+        plugins=[],
+        checkpoint_pattern='checkpoint_*.jsonl',
+        ckpt_start_time=ckpt_start_time,
+        bypass_old_ckpt_files_with_non_oop_errors=False,
+    )
+    monitor.run()
+    for leaf in run.experiment.leaf_nodes:
+      self.assertGreater(leaf.progress.prior_elapse, 0.0)
+
 
 if __name__ == '__main__':
   unittest.main()