diff --git a/homeassistant/components/open_router/config_flow.py b/homeassistant/components/open_router/config_flow.py
index 561dca60721..db9af4c0f26 100644
--- a/homeassistant/components/open_router/config_flow.py
+++ b/homeassistant/components/open_router/config_flow.py
@@ -173,6 +173,12 @@ class ConversationFlowHandler(OpenRouterSubentryFlowHandler):
             for api in llm.async_get_apis(self.hass)
         ]
 
+        if suggested_llm_apis := self.options.get(CONF_LLM_HASS_API):
+            valid_api_ids = {api["value"] for api in hass_apis}
+            self.options[CONF_LLM_HASS_API] = [
+                api for api in suggested_llm_apis if api in valid_api_ids
+            ]
+
         return self.async_show_form(
             step_id="init",
             data_schema=vol.Schema(
diff --git a/tests/components/open_router/test_config_flow.py b/tests/components/open_router/test_config_flow.py
index a980b10121d..523ef69aa3b 100644
--- a/tests/components/open_router/test_config_flow.py
+++ b/tests/components/open_router/test_config_flow.py
@@ -365,3 +365,51 @@ async def test_reconfigure_ai_task_abort(
     result = await mock_config_entry.start_subentry_reconfigure_flow(hass, subentry_id)
     assert result["type"] is FlowResultType.ABORT
     assert result["reason"] == reason
+
+
+@pytest.mark.parametrize(
+    ("current_llm_apis", "suggested_llm_apis", "expected_options"),
+    [
+        (["assist"], ["assist"], ["assist"]),
+        (["non-existent"], [], ["assist"]),
+        (["assist", "non-existent"], ["assist"], ["assist"]),
+    ],
+)
+async def test_reconfigure_conversation_subentry_llm_api_schema(
+    hass: HomeAssistant,
+    mock_open_router_client: AsyncMock,
+    mock_setup_entry: AsyncMock,
+    mock_config_entry: MockConfigEntry,
+    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."""
+    await setup_integration(hass, mock_config_entry)
+
+    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()
+
+    result = await mock_config_entry.start_subentry_reconfigure_flow(
+        hass, subentry.subentry_id
+    )
+
+    assert result["type"] is FlowResultType.FORM
+    assert result["step_id"] == "init"
+
+    # Only valid LLM APIs should be suggested and shown as options
+    schema = result["data_schema"].schema
+    key = next(k for k in schema if k == CONF_LLM_HASS_API)
+
+    assert key.default() == suggested_llm_apis
+
+    field_schema = schema[key]
+    assert field_schema.config
+    assert [
+        opt["value"] for opt in field_schema.config.get("options")
+    ] == expected_options