diff --git a/ax/preview/api/client.py b/ax/preview/api/client.py
index b212e3494c0..fa03192d987 100644
--- a/ax/preview/api/client.py
+++ b/ax/preview/api/client.py
@@ -467,7 +467,11 @@ def mark_trial_failed(self, trial_index: int) -> None:
 
         Saves to database on completion if db_config is present.
         """
-        ...
+        self._none_throws_experiment().trials[trial_index].mark_failed()
+
+        if self._db_config is not None:
+            # TODO[mpolson64] Save to database
+            ...
 
     def mark_trial_abandoned(self, trial_index: int) -> None:
         """
@@ -476,7 +480,11 @@ def mark_trial_abandoned(self, trial_index: int) -> None:
 
         Saves to database on completion if db_config is present.
         """
-        ...
+        self._none_throws_experiment().trials[trial_index].mark_abandoned()
+
+        if self._db_config is not None:
+            # TODO[mpolson64] Save to database
+            ...
 
     def mark_trial_early_stopped(self, trial_index: int) -> None:
         """
@@ -486,7 +494,11 @@ def mark_trial_early_stopped(self, trial_index: int) -> None:
 
         Saves to database on completion if db_config is present.
         """
-        ...
+        self._none_throws_experiment().trials[trial_index].mark_early_stopped()
+
+        if self._db_config is not None:
+            # TODO[mpolson64] Save to database
+            ...
 
     def run_trials(self, maximum_trials: int, options: OrchestrationConfig) -> None:
         """
diff --git a/ax/preview/api/tests/test_client.py b/ax/preview/api/tests/test_client.py
index b747c6d4916..116ee32be86 100644
--- a/ax/preview/api/tests/test_client.py
+++ b/ax/preview/api/tests/test_client.py
@@ -379,6 +379,72 @@ def test_get_next_trials(self) -> None:
         trials = client.get_next_trials(maximum_trials=2)
         self.assertEqual(len(trials), 1)
 
+    def test_mark_trial_failed(self) -> None:
+        client = Client()
+
+        client.configure_experiment(
+            ExperimentConfig(
+                parameters=[
+                    RangeParameterConfig(
+                        name="x1", parameter_type=ParameterType.FLOAT, bounds=(-1, 1)
+                    ),
+                ],
+                name="foo",
+            )
+        )
+        client.configure_optimization(objective="foo")
+
+        trial_index = [*client.get_next_trials(maximum_trials=1).keys()][0]
+        client.mark_trial_failed(trial_index=trial_index)
+        self.assertEqual(
+            none_throws(client._experiment).trials[trial_index].status,
+            TrialStatus.FAILED,
+        )
+
+    def test_mark_trial_abandoned(self) -> None:
+        client = Client()
+
+        client.configure_experiment(
+            ExperimentConfig(
+                parameters=[
+                    RangeParameterConfig(
+                        name="x1", parameter_type=ParameterType.FLOAT, bounds=(-1, 1)
+                    ),
+                ],
+                name="foo",
+            )
+        )
+        client.configure_optimization(objective="foo")
+
+        trial_index = [*client.get_next_trials(maximum_trials=1).keys()][0]
+        client.mark_trial_abandoned(trial_index=trial_index)
+        self.assertEqual(
+            none_throws(client._experiment).trials[trial_index].status,
+            TrialStatus.ABANDONED,
+        )
+
+    def test_mark_trial_early_stopped(self) -> None:
+        client = Client()
+
+        client.configure_experiment(
+            ExperimentConfig(
+                parameters=[
+                    RangeParameterConfig(
+                        name="x1", parameter_type=ParameterType.FLOAT, bounds=(-1, 1)
+                    ),
+                ],
+                name="foo",
+            )
+        )
+        client.configure_optimization(objective="foo")
+
+        trial_index = [*client.get_next_trials(maximum_trials=1).keys()][0]
+        client.mark_trial_early_stopped(trial_index=trial_index)
+        self.assertEqual(
+            none_throws(client._experiment).trials[trial_index].status,
+            TrialStatus.EARLY_STOPPED,
+        )
+
 
 class DummyRunner(IRunner):
     @override