diff --git a/qiskit_experiments/framework/experiment_data.py b/qiskit_experiments/framework/experiment_data.py
index 3428875086..133cbf7b3b 100644
--- a/qiskit_experiments/framework/experiment_data.py
+++ b/qiskit_experiments/framework/experiment_data.py
@@ -352,8 +352,8 @@ def __init__(
         # data storage
         self._result_data = ThreadSafeList()
         self._figures = ThreadSafeOrderedDict(self._db_data.figure_names)
-        self._analysis_results = AnalysisResultTable()
-
+        self._analysis_results = ThreadSafeOrderedDict()
+        self._completion_times = ThreadSafeOrderedDict()
         self._deleted_figures = deque()
         self._deleted_analysis_results = deque()
 
@@ -377,12 +377,7 @@ def experiment(self):
     @property
     def completion_times(self) -> Dict[str, datetime]:
         """Returns the completion times of the jobs."""
-        job_times = {}
-        for job_id, job in self._jobs.items():
-            if job is not None and "COMPLETED" in job.time_per_step():
-                job_times[job_id] = job.time_per_step().get("COMPLETED")
-
-        return job_times
+        return dict(self._completion_times)
 
     @property
     def tags(self) -> List[str]:
@@ -916,8 +911,11 @@ def _add_job_data(
                 pass
             self._add_result_data(job_result, jid)
             LOG.debug("Job data added [Job ID: %s]", jid)
-            # sets the endtime to be the time the last successful job was added
-            self.end_datetime = datetime.now()
+            completed_at = datetime.now()
+            with self._completion_times.lock:
+                self._completion_times[jid] = completed_at
+                # sets the end time to be the time the last successful job was added
+                self.end_datetime = completed_at
             return jid, True
         except Exception as ex:  # pylint: disable=broad-except
             # Handle cancelled jobs
@@ -2463,6 +2461,7 @@ def __json_encode__(self):
             "_deleted_figures": self._deleted_figures,
             "_deleted_analysis_results": self._deleted_analysis_results,
             "_result_data": self._result_data,
+            "_completion_times": self._completion_times,
             "_extra_data": self._extra_data,
             "_created_in_db": self._created_in_db,
             "_figures": self._safe_serialize_figures(),  # Convert figures to SVG
diff --git a/test/database_service/test_db_experiment_data.py b/test/database_service/test_db_experiment_data.py
index 3d83fa8512..2587284a8f 100644
--- a/test/database_service/test_db_experiment_data.py
+++ b/test/database_service/test_db_experiment_data.py
@@ -779,6 +779,19 @@ def _analysis(*args):  # pylint: disable = unused-argument
         self.assertEqual(exp_data.analysis_status(), AnalysisStatus.CANCELLED)
         self.assertEqual(exp_data.status(), ExperimentStatus.CANCELLED)
 
+    def test_completion_times(self):
+        """Test the completion_times property"""
+        jid = "1234"
+        job = mock.create_autospec(Job, instance=True)
+        job.job_id.return_value = jid
+        job.status = JobStatus.DONE
+
+        exp_data = ExperimentData(experiment_type="qiskit_test")
+        exp_data.add_jobs(job)
+        completion_times = exp_data.completion_times
+        self.assertTrue(jid in completion_times)
+        self.assertTrue(isinstance(completion_times[jid], datetime))
+
     def test_partial_cancel_analysis(self):
         """Test canceling experiment analysis."""