diff --git a/optimizely/decision_service.py b/optimizely/decision_service.py
index 28275ef6..be2be2c5 100644
--- a/optimizely/decision_service.py
+++ b/optimizely/decision_service.py
@@ -515,6 +515,11 @@ def get_variation(
                     'reasons': decide_reasons,
                     'variation': None
                 }
+            ignore_user_profile = True
+            self.logger.debug(
+                f'Skipping user profile service for CMAB experiment "{experiment.key}". '
+                f'CMAB decisions are dynamic and not stored for sticky bucketing.'
+            )
             variation_id = cmab_decision['variation_id'] if cmab_decision else None
             cmab_uuid = cmab_decision['cmab_uuid'] if cmab_decision else None
             variation = project_config.get_variation_from_id(experiment_key=experiment.key,
diff --git a/tests/test_decision_service.py b/tests/test_decision_service.py
index dbcb7436..b38a03b2 100644
--- a/tests/test_decision_service.py
+++ b/tests/test_decision_service.py
@@ -1074,6 +1074,124 @@ def test_get_variation_cmab_experiment_with_whitelisted_variation(self):
             mock_bucket.assert_not_called()
             mock_cmab_decision.assert_not_called()
 
+    def test_get_variation_cmab_experiment_does_not_save_user_profile(self):
+        """Test that CMAB experiments do not save bucketing decisions to user profile."""
+
+        # Create a user context
+        user = optimizely_user_context.OptimizelyUserContext(
+            optimizely_client=None,
+            logger=None,
+            user_id="test_user",
+            user_attributes={}
+        )
+
+        # Create a user profile service and tracker
+        user_profile_service = user_profile.UserProfileService()
+        user_profile_tracker = user_profile.UserProfileTracker(user.user_id, user_profile_service)
+
+        # Create a CMAB experiment
+        cmab_experiment = entities.Experiment(
+            '111150',
+            'cmab_experiment',
+            'Running',
+            '111150',
+            [],  # No audience IDs
+            {},
+            [
+                entities.Variation('111151', 'variation_1'),
+                entities.Variation('111152', 'variation_2')
+            ],
+            [
+                {'entityId': '111151', 'endOfRange': 5000},
+                {'entityId': '111152', 'endOfRange': 10000}
+            ],
+            cmab={'trafficAllocation': 5000}
+        )
+
+        with mock.patch('optimizely.helpers.experiment.is_experiment_running', return_value=True), \
+            mock.patch('optimizely.helpers.audience.does_user_meet_audience_conditions', return_value=[True, []]), \
+            mock.patch.object(self.decision_service.bucketer, 'bucket_to_entity_id',
+                              return_value=['$', []]), \
+            mock.patch.object(self.decision_service, 'cmab_service') as mock_cmab_service, \
+            mock.patch.object(self.project_config, 'get_variation_from_id',
+                              return_value=entities.Variation('111151', 'variation_1')), \
+            mock.patch.object(user_profile_tracker, 'update_user_profile') as mock_update_profile, \
+                mock.patch.object(self.decision_service, 'logger') as mock_logger:
+
+            # Configure CMAB service to return a decision
+            mock_cmab_service.get_decision.return_value = (
+                {
+                    'variation_id': '111151',
+                    'cmab_uuid': 'test-cmab-uuid-123'
+                },
+                []  # reasons list
+            )
+
+            # Call get_variation with the CMAB experiment and user profile tracker
+            variation_result = self.decision_service.get_variation(
+                self.project_config,
+                cmab_experiment,
+                user,
+                user_profile_tracker
+            )
+            variation = variation_result['variation']
+            cmab_uuid = variation_result['cmab_uuid']
+
+            # Verify the variation and cmab_uuid are returned
+            self.assertEqual(entities.Variation('111151', 'variation_1'), variation)
+            self.assertEqual('test-cmab-uuid-123', cmab_uuid)
+
+            # Verify user profile was NOT updated for CMAB experiment
+            mock_update_profile.assert_not_called()
+
+            # Verify debug log was called to explain CMAB exclusion
+            mock_logger.debug.assert_any_call(
+                'Skipping user profile service for CMAB experiment "cmab_experiment". '
+                'CMAB decisions are dynamic and not stored for sticky bucketing.'
+            )
+
+    def test_get_variation_standard_experiment_saves_user_profile(self):
+        """Test that standard (non-CMAB) experiments DO save bucketing decisions to user profile."""
+
+        user = optimizely_user_context.OptimizelyUserContext(
+            optimizely_client=None,
+            logger=None,
+            user_id="test_user",
+            user_attributes={}
+        )
+
+        # Create a user profile service and tracker
+        user_profile_service = user_profile.UserProfileService()
+        user_profile_tracker = user_profile.UserProfileTracker(user.user_id, user_profile_service)
+
+        # Get a standard (non-CMAB) experiment
+        experiment = self.project_config.get_experiment_from_key("test_experiment")
+
+        with mock.patch('optimizely.decision_service.DecisionService.get_whitelisted_variation',
+                        return_value=[None, []]), \
+            mock.patch('optimizely.decision_service.DecisionService.get_stored_variation',
+                       return_value=None), \
+            mock.patch('optimizely.helpers.audience.does_user_meet_audience_conditions',
+                       return_value=[True, []]), \
+            mock.patch('optimizely.bucketer.Bucketer.bucket',
+                       return_value=[entities.Variation("111129", "variation"), []]), \
+                mock.patch.object(user_profile_tracker, 'update_user_profile') as mock_update_profile:
+
+            # Call get_variation with standard experiment and user profile tracker
+            variation_result = self.decision_service.get_variation(
+                self.project_config,
+                experiment,
+                user,
+                user_profile_tracker
+            )
+            variation = variation_result['variation']
+
+            # Verify variation was returned
+            self.assertEqual(entities.Variation("111129", "variation"), variation)
+
+            # Verify user profile WAS updated for standard experiment
+            mock_update_profile.assert_called_once_with(experiment, variation)
+
 
 class FeatureFlagDecisionTests(base.BaseTest):
     def setUp(self):