diff --git a/CLAUDE.md b/CLAUDE.md
index 6d04a7b..26d9927 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -105,13 +105,13 @@ def __init__(
     field_name: str | None = None,
     is_flag: bool | None = None,
     # ... other keyword-only parameters
-    **_: Any,  # ignore unknown keys
+    **_: object,  # ignore unknown keys
 ) -> None:
 ```
 
 Key points:
 - Use `*` to enforce keyword-only arguments
-- Accept `**_: Any` to ignore unknown keys from the API (forward compatibility)
+- Accept `**_: object` to ignore unknown keys from the API (forward compatibility)
 - Use `| None = None` for optional parameters
 - Boolean fields can be `None` if not provided by API
 
@@ -252,7 +252,7 @@ def test_email(self) -> None:
        *,
        new_field: str | None = None,
        # ... other params
-       **_: Any,
+       **_: object,
    ) -> None:
    ```
 
@@ -281,7 +281,7 @@ When creating a new model class:
 2. **Follow the constructor pattern** from existing models
 3. **Use type hints** for all attributes
 4. **Use keyword-only arguments** with `*` separator
-5. **Accept `**_: Any`** to ignore unknown API keys
+5. **Accept `**_: object`** to ignore unknown API keys
 6. **Provide comprehensive docstrings** for all attributes
 7. **Add corresponding tests** with full coverage
 
@@ -376,7 +376,7 @@ Adding required parameters breaks existing code.
 - Always add new parameters as optional with defaults
 - Use keyword-only arguments (after `*`)
 - Never add required positional parameters to existing constructors
-- Use `**_: Any` to silently accept unknown parameters from API
+- Use `**_: object` to silently accept unknown parameters from API
 
 ## Code Style Requirements
 
diff --git a/HISTORY.rst b/HISTORY.rst
index 99fd48b..5c789fb 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -21,6 +21,12 @@ History
   ``aiohttp.encode_basic_auth()`` instead of the ``aiohttp.BasicAuth`` /
   ``auth=`` parameter, which are deprecated as of aiohttp 3.14.0. As a result,
   the minimum required ``aiohttp`` version is now 3.14.0.
+* The ``ip_address.anonymizer`` object may now contain a ``residential``
+  attribute. This is a ``geoip2.records.AnonymizerFeed`` object containing
+  residential proxy data for the network. It has the following fields:
+  ``confidence``, ``network_last_seen``, and ``provider_name``. It may be
+  populated even when no other ``anonymizer`` attributes are set. This
+  requires ``geoip2`` 5.3.0 or greater.
 
 3.2.0 (2025-11-20)
 ++++++++++++++++++
diff --git a/pyproject.toml b/pyproject.toml
index bb2eb62..73b713a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -92,8 +92,7 @@ ignorelist = ["id"]
 
 [tool.ruff.lint.per-file-ignores]
 "docs/*" = ["ALL"]
-"src/minfraud/models.py" = ["ANN401", "PLR0913"]
-"src/minfraud/webservice.py" = ["ANN401"]
+"src/minfraud/models.py" = ["PLR0913"]
 "tests/*" = ["ANN201", "D"]
 
 [tool.tox]
diff --git a/src/minfraud/models.py b/src/minfraud/models.py
index d86e2ba..8cfc45d 100644
--- a/src/minfraud/models.py
+++ b/src/minfraud/models.py
@@ -100,7 +100,7 @@ class GeoIP2Location(geoip2.records.Location):
     `RFC 3339 <https://datatracker.ietf.org/doc/html/rfc3339>`_. For instance, the
     local time in Boston might be returned as 2015-04-27T19:17:24-04:00."""
 
-    def __init__(self, *args: Any, **kwargs: Any) -> None:
+    def __init__(self, *args: Any, **kwargs: Any) -> None:  # noqa: ANN401
         """Initialize a GeoIP2Location instance."""
         self.local_time = kwargs.get("local_time")
         super().__init__(*args, **kwargs)
@@ -135,7 +135,7 @@ def __init__(
         location: dict[str, Any] | None = None,
         risk: float | None = None,
         risk_reasons: list[dict[str, Any]] | None = None,
-        **kwargs: Any,
+        **kwargs: Any,  # noqa: ANN401
     ) -> None:
         """Initialize an IPAddress instance."""
         # For raw attribute
@@ -161,7 +161,7 @@ class ScoreIPAddress(_Serializable):
     """This field contains the risk associated with the IP address. The value
     ranges from 0.01 to 99. A higher score indicates a higher risk."""
 
-    def __init__(self, *, risk: float | None = None, **_: Any) -> None:
+    def __init__(self, *, risk: float | None = None, **_: object) -> None:
         """Initialize a ScoreIPAddress instance."""
         self.risk = risk
 
@@ -197,7 +197,7 @@ def __init__(
         matches_provided_name: bool | None = None,
         phone_number: str | None = None,
         matches_provided_phone_number: bool | None = None,
-        **_: Any,
+        **_: object,
     ) -> None:
         """Initialize an Issuer instance."""
         self.name = name
@@ -239,7 +239,7 @@ def __init__(
         id: str | None = None,
         last_seen: str | None = None,
         local_time: str | None = None,
-        **_: Any,
+        **_: object,
     ) -> None:
         """Initialize a Device instance."""
         self.confidence = confidence
@@ -277,7 +277,7 @@ def __init__(
         action: str | None = None,
         reason: str | None = None,
         rule_label: str | None = None,
-        **_: Any,
+        **_: object,
     ) -> None:
         """Initialize a Disposition instance."""
         self.action = action
@@ -310,7 +310,7 @@ def __init__(
         status: str | None = None,
         last_visited_on: str | None = None,
         has_redirect: bool | None = None,
-        **_: Any,
+        **_: object,
     ) -> None:
         """Initialize an EmailDomainVisit instance."""
         self.status = status
@@ -354,7 +354,7 @@ def __init__(
         risk: float | None = None,
         volume: float | None = None,
         visit: dict[str, Any] | None = None,
-        **_: Any,
+        **_: object,
     ) -> None:
         """Initialize an EmailDomain instance."""
         self.first_seen = first_seen
@@ -498,7 +498,7 @@ def __init__(
         longitude: float | None = None,
         distance_to_ip_location: int | None = None,
         is_in_ip_country: bool | None = None,
-        **_: Any,
+        **_: object,
     ) -> None:
         """Initialize a BillingAddress instance."""
         self.is_postal_in_city = is_postal_in_city
@@ -553,7 +553,7 @@ def __init__(
         is_in_ip_country: bool | None = None,
         is_high_risk: bool | None = None,
         distance_to_billing_address: int | None = None,
-        **_: Any,
+        **_: object,
     ) -> None:
         """Initialize a ShippingAddress instance."""
         self.is_postal_in_city = is_postal_in_city
@@ -604,7 +604,7 @@ def __init__(
         matches_postal: bool | None = None,
         network_operator: str | None = None,
         number_type: str | None = None,
-        **_: Any,
+        **_: object,
     ) -> None:
         """Initialize a Phone instance."""
         self.country = country
@@ -639,7 +639,7 @@ def __init__(
         code: str | None = None,
         warning: str | None = None,
         input_pointer: str | None = None,
-        **_: Any,
+        **_: object,
     ) -> None:
         """Initialize a ServiceWarning instance."""
         self.code = code
@@ -783,7 +783,7 @@ def __init__(
         shipping_address: float | None = None,
         shipping_address_distance_to_ip_location: float | None = None,
         time_of_day: float | None = None,
-        **_: Any,
+        **_: object,
     ) -> None:
         """Initialize a Subscores instance."""
         self.avs_result = avs_result
@@ -897,7 +897,7 @@ def __init__(
         *,
         code: str | None = None,
         reason: str | None = None,
-        **_: Any,
+        **_: object,
     ) -> None:
         """Initialize a Reason instance."""
         self.code = code
@@ -922,7 +922,7 @@ def __init__(
         *,
         multiplier: float,
         reasons: list[dict[str, Any]] | None = None,
-        **_: Any,
+        **_: object,
     ) -> None:
         """Initialize a RiskScoreReason instance."""
         self.multiplier = multiplier
@@ -1030,7 +1030,7 @@ def __init__(
         subscores: dict[str, Any] | None = None,
         warnings: list[dict[str, Any]] | None = None,
         risk_score_reasons: list[dict[str, Any]] | None = None,
-        **_: Any,
+        **_: object,
     ) -> None:
         """Initialize a Factors instance."""
         self.billing_address = BillingAddress(**(billing_address or {}))
@@ -1136,7 +1136,7 @@ def __init__(
         shipping_address: dict[str, Any] | None = None,
         shipping_phone: dict[str, Any] | None = None,
         warnings: list[dict[str, Any]] | None = None,
-        **_: Any,
+        **_: object,
     ) -> None:
         """Initialize an Insights instance."""
         self.billing_address = BillingAddress(**(billing_address or {}))
@@ -1201,7 +1201,7 @@ def __init__(
         queries_remaining: int,
         risk_score: float,
         warnings: list[dict[str, Any]] | None = None,
-        **_: Any,
+        **_: object,
     ) -> None:
         """Initialize a Score instance."""
         self.disposition = Disposition(**(disposition or {}))
diff --git a/tests/data/factors-response.json b/tests/data/factors-response.json
index 1aee01f..9317084 100644
--- a/tests/data/factors-response.json
+++ b/tests/data/factors-response.json
@@ -28,7 +28,12 @@
       "is_residential_proxy": true,
       "is_tor_exit_node": true,
       "network_last_seen": "2025-01-15",
-      "provider_name": "TestVPN"
+      "provider_name": "TestVPN",
+      "residential": {
+        "confidence": 82,
+        "network_last_seen": "2026-05-11",
+        "provider_name": "quickshift"
+      }
     },
     "city": {
       "confidence": 42,
diff --git a/tests/data/insights-response.json b/tests/data/insights-response.json
index 14a4152..bcee439 100644
--- a/tests/data/insights-response.json
+++ b/tests/data/insights-response.json
@@ -28,7 +28,12 @@
       "is_residential_proxy": true,
       "is_tor_exit_node": true,
       "network_last_seen": "2025-01-15",
-      "provider_name": "TestVPN"
+      "provider_name": "TestVPN",
+      "residential": {
+        "confidence": 82,
+        "network_last_seen": "2026-05-11",
+        "provider_name": "quickshift"
+      }
     },
     "city": {
       "confidence": 42,
diff --git a/tests/test_models.py b/tests/test_models.py
index b7fa6c8..05cd2e9 100644
--- a/tests/test_models.py
+++ b/tests/test_models.py
@@ -197,6 +197,11 @@ def test_ip_address(self) -> None:
                 "is_tor_exit_node": True,
                 "network_last_seen": "2025-01-15",
                 "provider_name": "TestVPN",
+                "residential": {
+                    "confidence": 82,
+                    "network_last_seen": "2026-05-11",
+                    "provider_name": "quickshift",
+                },
             },
             traits={
                 "is_anonymous": True,
@@ -238,6 +243,25 @@ def test_ip_address(self) -> None:
         )
         self.assertEqual("TestVPN", address.anonymizer.provider_name)
 
+        # Test anonymizer.residential attribute
+        self.assertEqual(82, address.anonymizer.residential.confidence)
+        self.assertEqual(
+            datetime.date(2026, 5, 11),
+            address.anonymizer.residential.network_last_seen,
+        )
+        self.assertEqual("quickshift", address.anonymizer.residential.provider_name)
+
+        # Test to_dict() serialization of anonymizer.residential. The date
+        # is serialized in its ISO 8601 format.
+        self.assertEqual(
+            {
+                "confidence": 82,
+                "network_last_seen": "2026-05-11",
+                "provider_name": "quickshift",
+            },
+            address.to_dict()["anonymizer"]["residential"],
+        )
+
         self.assertEqual("ANONYMOUS_IP", address.risk_reasons[0].code)
         self.assertEqual(
             "The IP address belongs to an anonymous network. "
@@ -252,6 +276,23 @@ def test_ip_address(self) -> None:
             address.risk_reasons[1].reason,
         )
 
+    def test_ip_address_anonymizer_without_residential(self) -> None:
+        address = IPAddress(
+            ["en"],
+            anonymizer={
+                "is_anonymous": True,
+                "provider_name": "TestVPN",
+            },
+        )
+
+        self.assertIsNone(address.anonymizer.residential.confidence)
+        self.assertIsNone(address.anonymizer.residential.network_last_seen)
+        self.assertIsNone(address.anonymizer.residential.provider_name)
+
+        # Empty nested records are skipped during serialization, so there
+        # should be no residential key.
+        self.assertNotIn("residential", address.to_dict()["anonymizer"])
+
     def test_empty_address(self) -> None:
         address = IPAddress([])
         self.assertEqual([], address.risk_reasons)
diff --git a/tests/test_webservice.py b/tests/test_webservice.py
index 2dfff37..d949642 100644
--- a/tests/test_webservice.py
+++ b/tests/test_webservice.py
@@ -236,6 +236,14 @@ def test_200(self) -> None:
             self.assertEqual("310", model.ip_address.traits.mobile_country_code)
             self.assertEqual("004", model.ip_address.traits.mobile_network_code)
             self.assertEqual("ANONYMOUS_IP", model.ip_address.risk_reasons[0].code)
+            self.assertEqual(
+                82,
+                model.ip_address.anonymizer.residential.confidence,
+            )
+            self.assertEqual(
+                "quickshift",
+                model.ip_address.anonymizer.residential.provider_name,
+            )
 
     def test_authorization_header(self) -> None:
         # Credentials must be sent via the Authorization header rather than the