diff --git a/homeassistant/components/openai_conversation/__init__.py b/homeassistant/components/openai_conversation/__init__.py
index ad2c898bcd1f..ac25e4ec05e5 100644
--- a/homeassistant/components/openai_conversation/__init__.py
+++ b/homeassistant/components/openai_conversation/__init__.py
@@ -55,6 +55,7 @@ from .const import (
     LOGGER,
     RECOMMENDED_AI_TASK_OPTIONS,
     RECOMMENDED_CHAT_MODEL,
+    RECOMMENDED_CONVERSATION_REASONING_EFFORT,
     RECOMMENDED_MAX_TOKENS,
     RECOMMENDED_REASONING_EFFORT,
     RECOMMENDED_REASONING_SUMMARY,
@@ -217,7 +218,10 @@ async def async_setup(hass: HomeAssistant, config: ConfigType) -> bool:
         if model.startswith(("o", "gpt-5")):
             model_args["reasoning"] = {
                 "effort": conversation_subentry.data.get(
-                    CONF_REASONING_EFFORT, RECOMMENDED_REASONING_EFFORT
+                    CONF_REASONING_EFFORT,
+                    RECOMMENDED_CONVERSATION_REASONING_EFFORT
+                    if model == RECOMMENDED_CHAT_MODEL
+                    else RECOMMENDED_REASONING_EFFORT,
                 )
             }
 
diff --git a/homeassistant/components/openai_conversation/ai_task.py b/homeassistant/components/openai_conversation/ai_task.py
index 681ea6aaaf7a..1f3d9e65315e 100644
--- a/homeassistant/components/openai_conversation/ai_task.py
+++ b/homeassistant/components/openai_conversation/ai_task.py
@@ -16,6 +16,7 @@ from homeassistant.util.json import json_loads
 from .const import (
     CONF_CHAT_MODEL,
     CONF_IMAGE_MODEL,
+    RECOMMENDED_AI_TASK_REASONING_EFFORT,
     RECOMMENDED_CHAT_MODEL,
     RECOMMENDED_IMAGE_MODEL,
     UNSUPPORTED_IMAGE_MODELS,
@@ -52,6 +53,8 @@ class OpenAITaskEntity(
 ):
     """OpenAI AI Task entity."""
 
+    _recommended_reasoning_effort = RECOMMENDED_AI_TASK_REASONING_EFFORT
+
     def __init__(self, entry: OpenAIConfigEntry, subentry: ConfigSubentry) -> None:
         """Initialize the entity."""
         super().__init__(entry, subentry)
diff --git a/homeassistant/components/openai_conversation/const.py b/homeassistant/components/openai_conversation/const.py
index 8c9fde6e5785..16498fe3dbd5 100644
--- a/homeassistant/components/openai_conversation/const.py
+++ b/homeassistant/components/openai_conversation/const.py
@@ -44,6 +44,8 @@ RECOMMENDED_IMAGE_MODEL = "gpt-image-2"
 RECOMMENDED_MAX_TOKENS = 3000
 RECOMMENDED_PRO_MODE = False
 RECOMMENDED_REASONING_EFFORT = "low"
+RECOMMENDED_CONVERSATION_REASONING_EFFORT = "minimal"
+RECOMMENDED_AI_TASK_REASONING_EFFORT = "medium"
 RECOMMENDED_STORE_RESPONSES = False
 RECOMMENDED_REASONING_SUMMARY = "auto"
 RECOMMENDED_SERVICE_TIER = "auto"
diff --git a/homeassistant/components/openai_conversation/conversation.py b/homeassistant/components/openai_conversation/conversation.py
index 78c531f87162..148ef389e45c 100644
--- a/homeassistant/components/openai_conversation/conversation.py
+++ b/homeassistant/components/openai_conversation/conversation.py
@@ -9,7 +9,7 @@ from homeassistant.core import HomeAssistant
 from homeassistant.helpers.entity_platform import AddConfigEntryEntitiesCallback
 
 from . import OpenAIConfigEntry
-from .const import DOMAIN
+from .const import DOMAIN, RECOMMENDED_CONVERSATION_REASONING_EFFORT
 from .entity import OpenAIBaseLLMEntity
 
 # Max number of back and forth with the LLM to generate a response
@@ -39,6 +39,7 @@ class OpenAIConversationEntity(
     """OpenAI conversation agent."""
 
     _attr_supports_streaming = True
+    _recommended_reasoning_effort = RECOMMENDED_CONVERSATION_REASONING_EFFORT
 
     def __init__(self, entry: OpenAIConfigEntry, subentry: ConfigSubentry) -> None:
         """Initialize the agent."""
diff --git a/homeassistant/components/openai_conversation/entity.py b/homeassistant/components/openai_conversation/entity.py
index 5fa447e9b925..543017b64ae0 100644
--- a/homeassistant/components/openai_conversation/entity.py
+++ b/homeassistant/components/openai_conversation/entity.py
@@ -480,6 +480,8 @@ class OpenAIBaseLLMEntity(Entity):
 
     _attr_has_entity_name = True
     _attr_name: str | None = None
+    # Effort used in recommended mode, must be supported by RECOMMENDED_CHAT_MODEL
+    _recommended_reasoning_effort = RECOMMENDED_REASONING_EFFORT
 
     def __init__(self, entry: OpenAIConfigEntry, subentry: ConfigSubentry) -> None:
         """Initialize the entity."""
@@ -523,10 +525,14 @@ class OpenAIBaseLLMEntity(Entity):
         )
 
         if model_args["model"].startswith(("o", "gpt-5")):
+            # Other models support a different set of efforts
+            recommended_effort = (
+                self._recommended_reasoning_effort
+                if model_args["model"] == RECOMMENDED_CHAT_MODEL
+                else RECOMMENDED_REASONING_EFFORT
+            )
             reasoning: Reasoning = {
-                "effort": options.get(
-                    CONF_REASONING_EFFORT, RECOMMENDED_REASONING_EFFORT
-                )
+                "effort": options.get(CONF_REASONING_EFFORT, recommended_effort)
                 if not model_args["model"].startswith("gpt-5-pro")
                 else "high",  # GPT-5 pro only supports reasoning.effort: high
             }
diff --git a/tests/components/openai_conversation/snapshots/test_conversation.ambr b/tests/components/openai_conversation/snapshots/test_conversation.ambr
index dac962c59c7f..d5e7edc35ae3 100644
--- a/tests/components/openai_conversation/snapshots/test_conversation.ambr
+++ b/tests/components/openai_conversation/snapshots/test_conversation.ambr
@@ -297,7 +297,7 @@
     }),
   ])
 # ---
-# name: test_model_args[subentry_options0]
+# name: test_model_args[pro_mode]
   dict({
     'include': list([
       'reasoning.encrypted_content',
@@ -318,6 +318,25 @@
     }),
   })
 # ---
+# name: test_model_args[recommended]
+  dict({
+    'include': list([
+      'reasoning.encrypted_content',
+    ]),
+    'max_output_tokens': 3000,
+    'model': 'gpt-5-nano',
+    'reasoning': dict({
+      'effort': 'minimal',
+      'summary': 'auto',
+    }),
+    'service_tier': 'auto',
+    'store': False,
+    'stream': True,
+    'text': dict({
+      'verbosity': 'medium',
+    }),
+  })
+# ---
 # name: test_web_search[False]
   list([
     dict({
diff --git a/tests/components/openai_conversation/test_ai_task.py b/tests/components/openai_conversation/test_ai_task.py
index fe9f414c68fe..7b3624f9ee97 100644
--- a/tests/components/openai_conversation/test_ai_task.py
+++ b/tests/components/openai_conversation/test_ai_task.py
@@ -68,6 +68,26 @@ async def test_generate_data(
     assert mock_create_stream.call_args.kwargs["store"] is expected_store
 
 
+@pytest.mark.usefixtures("mock_init_component", "mock_config_entry")
+async def test_recommended_reasoning_effort(
+    hass: HomeAssistant,
+    mock_create_stream: AsyncMock,
+) -> None:
+    """Test AI Task reasons more than conversation with recommended settings."""
+    mock_create_stream.return_value = [
+        create_message_item(id="msg_A", text="The test data", output_index=0)
+    ]
+
+    await ai_task.async_generate_data(
+        hass,
+        task_name="Test Task",
+        entity_id="ai_task.openai_ai_task",
+        instructions="Generate test data",
+    )
+
+    assert mock_create_stream.call_args.kwargs["reasoning"]["effort"] == "medium"
+
+
 @pytest.mark.usefixtures("mock_init_component")
 async def test_generate_structured_data(
     hass: HomeAssistant,
diff --git a/tests/components/openai_conversation/test_conversation.py b/tests/components/openai_conversation/test_conversation.py
index 933e57bc7d1b..ace78bb841be 100644
--- a/tests/components/openai_conversation/test_conversation.py
+++ b/tests/components/openai_conversation/test_conversation.py
@@ -821,7 +821,13 @@ async def test_flex_tier_retry(
 
 
 @pytest.mark.parametrize(
-    "subentry_options", [{CONF_CHAT_MODEL: "gpt-5.6-sol", CONF_PRO_MODE: True}]
+    "subentry_options",
+    [
+        pytest.param(
+            {CONF_CHAT_MODEL: "gpt-5.6-sol", CONF_PRO_MODE: True}, id="pro_mode"
+        ),
+        pytest.param({}, id="recommended"),
+    ],
 )
 async def test_model_args(
     hass: HomeAssistant,
diff --git a/tests/components/openai_conversation/test_init.py b/tests/components/openai_conversation/test_init.py
index 20466fa29b03..1b4f2a4550bd 100644
--- a/tests/components/openai_conversation/test_init.py
+++ b/tests/components/openai_conversation/test_init.py
@@ -429,7 +429,7 @@ async def test_generate_content_service(
     service_data["config_entry"] = mock_config_entry.entry_id
     expected_args["model"] = "gpt-5-nano"
     expected_args["max_output_tokens"] = 3000
-    expected_args["reasoning"] = {"effort": "low"}
+    expected_args["reasoning"] = {"effort": "minimal"}
     expected_args["user"] = None
     expected_args["store"] = store_responses
     expected_args["input"][0]["type"] = "message"