diff --git a/homeassistant/auth/permissions/__init__.py b/homeassistant/auth/permissions/__init__.py
index 101c331b842..935f9bfbf65 100644
--- a/homeassistant/auth/permissions/__init__.py
+++ b/homeassistant/auth/permissions/__init__.py
@@ -8,13 +8,23 @@ import voluptuous as vol
 
 from .const import CAT_ENTITIES
 from .entities import ENTITY_POLICY_SCHEMA, compile_entities
-from .merge import merge_policies  # noqa: F401
+from .merge import merge_policies
 from .models import PermissionLookup
 from .types import PolicyType
 from .util import test_all
 
 POLICY_SCHEMA = vol.Schema({vol.Optional(CAT_ENTITIES): ENTITY_POLICY_SCHEMA})
 
+__all__ = [
+    "POLICY_SCHEMA",
+    "merge_policies",
+    "PermissionLookup",
+    "PolicyType",
+    "AbstractPermissions",
+    "PolicyPermissions",
+    "OwnerPermissions",
+]
+
 
 class AbstractPermissions:
     """Default permissions class."""
diff --git a/homeassistant/components/aussie_broadband/sensor.py b/homeassistant/components/aussie_broadband/sensor.py
index 5bfa6a4770a..2ce8aaca9c4 100644
--- a/homeassistant/components/aussie_broadband/sensor.py
+++ b/homeassistant/components/aussie_broadband/sensor.py
@@ -11,7 +11,8 @@ from homeassistant.components.sensor import (
 from homeassistant.config_entries import ConfigEntry
 from homeassistant.const import DATA_KILOBYTES, DATA_MEGABYTES, TIME_DAYS
 from homeassistant.core import HomeAssistant
-from homeassistant.helpers.entity import DeviceEntryType, DeviceInfo
+from homeassistant.helpers.device_registry import DeviceEntryType
+from homeassistant.helpers.entity import DeviceInfo
 from homeassistant.helpers.entity_platform import AddEntitiesCallback
 from homeassistant.helpers.update_coordinator import CoordinatorEntity
 
diff --git a/homeassistant/components/metoffice/helpers.py b/homeassistant/components/metoffice/helpers.py
index e7518f86b5b..31ac4c141a9 100644
--- a/homeassistant/components/metoffice/helpers.py
+++ b/homeassistant/components/metoffice/helpers.py
@@ -5,7 +5,7 @@ import logging
 import datapoint
 
 from homeassistant.helpers.update_coordinator import UpdateFailed
-from homeassistant.util import utcnow
+from homeassistant.util.dt import utcnow
 
 from .data import MetOfficeData
 
diff --git a/homeassistant/components/sma/__init__.py b/homeassistant/components/sma/__init__.py
index 74a2581632c..556c2a16b6c 100644
--- a/homeassistant/components/sma/__init__.py
+++ b/homeassistant/components/sma/__init__.py
@@ -7,7 +7,7 @@ from typing import TYPE_CHECKING
 
 import pysma
 
-from homeassistant.config_entries import ConfigEntry, ConfigEntryNotReady
+from homeassistant.config_entries import ConfigEntry
 from homeassistant.const import (
     CONF_HOST,
     CONF_PASSWORD,
@@ -17,6 +17,7 @@ from homeassistant.const import (
     EVENT_HOMEASSISTANT_STOP,
 )
 from homeassistant.core import HomeAssistant
+from homeassistant.exceptions import ConfigEntryNotReady
 from homeassistant.helpers.aiohttp_client import async_get_clientsession
 from homeassistant.helpers.entity import DeviceInfo
 from homeassistant.helpers.update_coordinator import DataUpdateCoordinator, UpdateFailed
diff --git a/homeassistant/components/zwave_js/climate.py b/homeassistant/components/zwave_js/climate.py
index 0c779eeb78f..6df95d9bbfc 100644
--- a/homeassistant/components/zwave_js/climate.py
+++ b/homeassistant/components/zwave_js/climate.py
@@ -55,7 +55,7 @@ from homeassistant.const import (
 from homeassistant.core import HomeAssistant, callback
 from homeassistant.helpers.dispatcher import async_dispatcher_connect
 from homeassistant.helpers.entity_platform import AddEntitiesCallback
-from homeassistant.helpers.temperature import convert_temperature
+from homeassistant.util.temperature import convert as convert_temperature
 
 from .const import DATA_CLIENT, DOMAIN
 from .discovery import ZwaveDiscoveryInfo
diff --git a/homeassistant/helpers/check_config.py b/homeassistant/helpers/check_config.py
index 3da444a8549..3bda89c9a73 100644
--- a/homeassistant/helpers/check_config.py
+++ b/homeassistant/helpers/check_config.py
@@ -10,7 +10,7 @@ from typing import NamedTuple
 import voluptuous as vol
 
 from homeassistant import loader
-from homeassistant.config import (
+from homeassistant.config import (  # type: ignore[attr-defined]
     CONF_CORE,
     CONF_PACKAGES,
     CORE_CONFIG_SCHEMA,
diff --git a/mypy.ini b/mypy.ini
index 5707d701f6f..886b0fce2ce 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -22,6 +22,9 @@ no_implicit_optional = true
 warn_return_any = true
 warn_unreachable = true
 
+[mypy-homeassistant.*]
+no_implicit_reexport = true
+
 [mypy-homeassistant.exceptions]
 disallow_any_generics = true
 
@@ -86,6 +89,7 @@ disallow_untyped_defs = false
 no_implicit_optional = false
 warn_return_any = false
 warn_unreachable = false
+no_implicit_reexport = false
 
 [mypy-homeassistant.components]
 check_untyped_defs = true
@@ -97,6 +101,7 @@ disallow_untyped_defs = true
 no_implicit_optional = true
 warn_return_any = true
 warn_unreachable = true
+no_implicit_reexport = true
 
 [mypy-homeassistant.components.abode.*]
 check_untyped_defs = true
@@ -2012,6 +2017,9 @@ no_implicit_optional = true
 warn_return_any = true
 warn_unreachable = true
 
+[mypy-homeassistant.components.diagnostics.*]
+no_implicit_reexport = true
+
 [mypy-tests.*]
 check_untyped_defs = false
 disallow_incomplete_defs = false
diff --git a/script/hassfest/mypy_config.py b/script/hassfest/mypy_config.py
index 7fc5e161923..d2bd437c2d9 100644
--- a/script/hassfest/mypy_config.py
+++ b/script/hassfest/mypy_config.py
@@ -81,6 +81,12 @@ IGNORED_MODULES: Final[list[str]] = [
     "homeassistant.components.zwave.*",
 ]
 
+# Component modules which should set no_implicit_reexport = true.
+NO_IMPLICIT_REEXPORT_MODULES: set[str] = {
+    "homeassistant.components",
+    "homeassistant.components.diagnostics.*",
+}
+
 HEADER: Final = """
 # Automatically generated by hassfest.
 #
@@ -165,7 +171,12 @@ def generate_and_validate(config: Config) -> str:
             )
 
     # Validate that all modules exist.
-    all_modules = strict_modules + strict_core_modules + IGNORED_MODULES
+    all_modules = (
+        strict_modules
+        + strict_core_modules
+        + IGNORED_MODULES
+        + list(NO_IMPLICIT_REEXPORT_MODULES)
+    )
     for module in all_modules:
         if module.endswith(".*"):
             module_path = Path(module[:-2].replace(".", os.path.sep))
@@ -193,6 +204,12 @@ def generate_and_validate(config: Config) -> str:
     for key in STRICT_SETTINGS:
         mypy_config.set(general_section, key, "true")
 
+    # By default enable no_implicit_reexport only for homeassistant.*
+    # Disable it afterwards for all components
+    components_section = "mypy-homeassistant.*"
+    mypy_config.add_section(components_section)
+    mypy_config.set(components_section, "no_implicit_reexport", "true")
+
     for core_module in strict_core_modules:
         core_section = f"mypy-{core_module}"
         mypy_config.add_section(core_section)
@@ -204,12 +221,20 @@ def generate_and_validate(config: Config) -> str:
     mypy_config.add_section(components_section)
     for key in STRICT_SETTINGS:
         mypy_config.set(components_section, key, "false")
+    mypy_config.set(components_section, "no_implicit_reexport", "false")
 
     for strict_module in strict_modules:
         strict_section = f"mypy-{strict_module}"
         mypy_config.add_section(strict_section)
         for key in STRICT_SETTINGS:
             mypy_config.set(strict_section, key, "true")
+        if strict_module in NO_IMPLICIT_REEXPORT_MODULES:
+            mypy_config.set(strict_section, "no_implicit_reexport", "true")
+
+    for reexport_module in NO_IMPLICIT_REEXPORT_MODULES.difference(strict_modules):
+        reexport_section = f"mypy-{reexport_module}"
+        mypy_config.add_section(reexport_section)
+        mypy_config.set(reexport_section, "no_implicit_reexport", "true")
 
     # Disable strict checks for tests
     tests_section = "mypy-tests.*"