diff --git a/src/geocodio/client.py b/src/geocodio/client.py
index fdeabe0..b74147f 100644
--- a/src/geocodio/client.py
+++ b/src/geocodio/client.py
@@ -414,6 +414,7 @@ def _parse_geocoding_response(self, response_json: dict) -> GeocodingResponse:
                         source=top.get("source", ""),
                         query=query,
                         fields=self._parse_fields(top.get("fields")),
+                        stable_address_key=top.get("stable_address_key"),
                     )
                 )
             return GeocodingResponse(results=results)
@@ -430,6 +431,7 @@ def _parse_geocoding_response(self, response_json: dict) -> GeocodingResponse:
                 accuracy_type=res.get("accuracy_type", ""),
                 source=res.get("source", ""),
                 fields=self._parse_fields(res.get("fields")),
+                stable_address_key=res.get("stable_address_key"),
             )
             for res in response_json.get("results", [])
         ]
diff --git a/src/geocodio/models.py b/src/geocodio/models.py
index 3eca092..c4085a2 100644
--- a/src/geocodio/models.py
+++ b/src/geocodio/models.py
@@ -671,6 +671,7 @@ class GeocodingResult:
     source: str
     fields: Optional[GeocodioFields] = None
     query: str = ""
+    stable_address_key: Optional[str] = None
 
     @property
     def matched(self) -> bool:
diff --git a/tests/e2e/test_api.py b/tests/e2e/test_api.py
index 2036886..5a661b3 100644
--- a/tests/e2e/test_api.py
+++ b/tests/e2e/test_api.py
@@ -51,6 +51,32 @@ def test_integration_geocode(client):
     assert components.postal_code is not None
 
 
+def test_integration_stable_address_key(client):
+    """Verify stable_address_key is exposed on real single, reverse, and batch calls."""
+    # Single forward geocode
+    single = client.geocode("1109 N Highland St, Arlington, VA").results[0]
+    assert single.stable_address_key is not None
+    assert isinstance(single.stable_address_key, str)
+    assert single.stable_address_key != ""
+
+    # Reverse geocode (White House)
+    reverse = client.reverse((38.897699, -77.036547)).results[0]
+    assert reverse.stable_address_key is not None
+    assert isinstance(reverse.stable_address_key, str)
+
+    # Batch geocode (nested response format)
+    batch = client.geocode(
+        ["3730 N Clark St, Chicago, IL", "638 E 13th Ave, Denver, CO"]
+    )
+    for result in batch.results:
+        assert result.stable_address_key is not None
+        assert isinstance(result.stable_address_key, str)
+
+    # The key should be stable: the same address returns the same key.
+    again = client.geocode("1109 N Highland St, Arlington, VA").results[0]
+    assert again.stable_address_key == single.stable_address_key
+
+
 def test_integration_reverse(client):
     """Test real reverse geocoding API call."""
     # Test coordinates (White House)
diff --git a/tests/unit/test_geocode.py b/tests/unit/test_geocode.py
index ae24bc5..ce8915b 100644
--- a/tests/unit/test_geocode.py
+++ b/tests/unit/test_geocode.py
@@ -34,6 +34,7 @@ def sample_payload() -> dict:
                         "observes_dst": True,
                     }
                 },
+                "stable_address_key": "abc123stablekey",
             }
         ],
     }
@@ -67,6 +68,8 @@ def response_callback(request):
     tz = resp.results[0].fields.timezone
     assert tz.name == "America/New_York"
     assert tz.observes_dst is True
+    # stable address key (v2 returns this on every result)
+    assert resp.results[0].stable_address_key == "abc123stablekey"
 
 
 def test_geocode_batch(client, httpx_mock):
@@ -820,3 +823,92 @@ def batch_response_callback(request):
     assert unmatched.location is None
     assert unmatched.query == "qwertyuiop asdfghjkl zxcvbnm"
     assert unmatched.formatted_address == ""
+
+def test_geocode_batch_exposes_stable_address_key(client, httpx_mock):
+    """stable_address_key is parsed from the nested batch response format."""
+    addresses = ["1109 N Highland St, Arlington, VA"]
+
+    def batch_response_callback(request):
+        return httpx.Response(
+            200,
+            json={
+                "results": [
+                    {
+                        "query": "1109 N Highland St, Arlington, VA",
+                        "response": {
+                            "results": [
+                                {
+                                    "address_components": {
+                                        "number": "1109",
+                                        "street": "Highland",
+                                        "suffix": "St",
+                                        "city": "Arlington",
+                                        "state_province": "VA",
+                                        "postal_code": "22201",
+                                        "country": "US",
+                                    },
+                                    "formatted_address": "1109 N Highland St, Arlington, VA 22201",
+                                    "location": {"lat": 38.886672, "lng": -77.094735},
+                                    "accuracy": 1,
+                                    "accuracy_type": "rooftop",
+                                    "source": "Arlington",
+                                    "stable_address_key": "arlington-stable-key",
+                                }
+                            ]
+                        },
+                    },
+                ]
+            },
+        )
+
+    httpx_mock.add_callback(
+        callback=batch_response_callback,
+        url=httpx.URL("https://api.test/v2/geocode"),
+        match_headers={"Authorization": "Bearer TEST_KEY"},
+    )
+
+    resp = client.geocode(addresses)
+
+    assert resp.results[0].stable_address_key == "arlington-stable-key"
+
+
+def test_geocode_stable_address_key_absent_is_none(client, httpx_mock):
+    """stable_address_key defaults to None when the API omits it."""
+
+    def response_callback(request):
+        return httpx.Response(
+            200,
+            json={
+                "results": [
+                    {
+                        "address_components": {
+                            "number": "1109",
+                            "street": "Highland",
+                            "suffix": "St",
+                            "city": "Arlington",
+                            "state_province": "VA",
+                            "postal_code": "22201",
+                            "country": "US",
+                        },
+                        "formatted_address": "1109 N Highland St, Arlington, VA 22201",
+                        "location": {"lat": 38.886672, "lng": -77.094735},
+                        "accuracy": 1,
+                        "accuracy_type": "rooftop",
+                        "source": "Arlington",
+                    }
+                ],
+            },
+        )
+
+    httpx_mock.add_callback(
+        callback=response_callback,
+        url=httpx.URL(
+            "https://api.test/v2/geocode",
+            params={"q": "1109 N Highland St, Arlington, VA"},
+        ),
+        match_headers={"Authorization": "Bearer TEST_KEY"},
+    )
+
+    resp = client.geocode("1109 N Highland St, Arlington, VA")
+
+    assert resp.results[0].stable_address_key is None