diff --git a/homeassistant/components/openai_conversation/config_flow.py b/homeassistant/components/openai_conversation/config_flow.py
index 5cc604ca16b..ed37569202c 100644
--- a/homeassistant/components/openai_conversation/config_flow.py
+++ b/homeassistant/components/openai_conversation/config_flow.py
@@ -237,10 +237,13 @@ class OpenAISubentryFlowHandler(ConfigSubentryFlow):
             )
             for api in llm.async_get_apis(self.hass)
         ]
-        if (suggested_llm_apis := options.get(CONF_LLM_HASS_API)) and isinstance(
-            suggested_llm_apis, str
-        ):
-            options[CONF_LLM_HASS_API] = [suggested_llm_apis]
+        if suggested_llm_apis := options.get(CONF_LLM_HASS_API):
+            if isinstance(suggested_llm_apis, str):
+                suggested_llm_apis = [suggested_llm_apis]
+            valid_apis = {api.id for api in llm.async_get_apis(self.hass)}
+            options[CONF_LLM_HASS_API] = [
+                api for api in suggested_llm_apis if api in valid_apis
+            ]
 
         step_schema: VolDictType = {}
 
diff --git a/tests/components/openai_conversation/test_config_flow.py b/tests/components/openai_conversation/test_config_flow.py
index 14a6ce49b2e..59c70d28912 100644
--- a/tests/components/openai_conversation/test_config_flow.py
+++ b/tests/components/openai_conversation/test_config_flow.py
@@ -1086,3 +1086,52 @@ async def test_reauth(hass: HomeAssistant) -> None:
     assert result["type"] is FlowResultType.ABORT
     assert result["reason"] == "reauth_successful"
     assert mock_config_entry.data[CONF_API_KEY] == "new_api_key"
+
+
+@pytest.mark.parametrize(
+    ("current_llm_apis", "suggested_llm_apis", "expected_options"),
+    [
+        ("assist", ["assist"], ["assist"]),
+        (["assist"], ["assist"], ["assist"]),
+        ("non-existent", [], ["assist"]),
+        (["non-existent"], [], ["assist"]),
+        (["assist", "non-existent"], ["assist"], ["assist"]),
+    ],
+)
+async def test_reconfigure_conversation_subentry_llm_api_schema(
+    hass: HomeAssistant,
+    mock_config_entry: MockConfigEntry,
+    mock_init_component,
+    current_llm_apis: list[str],
+    suggested_llm_apis: list[str],
+    expected_options: list[str],
+) -> None:
+    """Test llm_hass_api field values when reconfiguring a conversation subentry."""
+    subentry = next(iter(mock_config_entry.subentries.values()))
+    hass.config_entries.async_update_subentry(
+        mock_config_entry,
+        subentry,
+        data={**subentry.data, CONF_LLM_HASS_API: current_llm_apis},
+    )
+    await hass.async_block_till_done()
+
+    with patch(
+        "homeassistant.components.openai_conversation.config_flow.openai.AsyncOpenAI.models",
+    ):
+        subentry_flow = await mock_config_entry.start_subentry_reconfigure_flow(
+            hass, subentry.subentry_id
+        )
+
+    assert subentry_flow["type"] is FlowResultType.FORM
+    assert subentry_flow["step_id"] == "init"
+
+    # Only valid LLM APIs should be suggested and shown as options
+    schema = subentry_flow["data_schema"].schema
+    key = next(k for k in schema if k == CONF_LLM_HASS_API)
+    assert key.description
+    assert key.description.get("suggested_value") == suggested_llm_apis
+    field_schema = schema[key]
+    assert field_schema.config
+    assert [
+        opt["value"] for opt in field_schema.config.get("options")
+    ] == expected_options