diff --git a/app/main.py b/app/main.py
index c989c2a..84650d9 100644
--- a/app/main.py
+++ b/app/main.py
@@ -126,6 +126,8 @@ def custom_openapi():
                     "The schools are scraped as part of the [jedeschule.de](https://jedeschule.de) project."
                     "You can find the source code for the [API](https://github.com/codeforberlin/jedeschule-api) and "
                     "the [scrapers](https://github.com/datenschule/jedeschule-scraper) on Github. \n\n"
+                    "Each school may include `state_key` when the scraper has stored it (same "
+                    "Bundesland codes as the `state` filter).\n\n"
                     "For more information about the available endpoints, check the documentation below.",
         routes=app.routes,
     )
diff --git a/app/models.py b/app/models.py
index 9c0a519..a08daea 100644
--- a/app/models.py
+++ b/app/models.py
@@ -8,6 +8,8 @@
 class School(Base):
     __tablename__ = 'schools'
     id = Column(String, primary_key=True)
+    # ISO 3166-2:DE code without DE- prefix; set by jedeschule-scraper (Land spider `state_key`).
+    state_key = Column(String, nullable=True)
     name = Column(String)
     address = Column(String)
     address2 = Column(String)
diff --git a/app/schemas.py b/app/schemas.py
index 0953d94..cad210e 100644
--- a/app/schemas.py
+++ b/app/schemas.py
@@ -5,9 +5,12 @@
 from typing import Optional, List
 
 from geoalchemy2.shape import to_shape
-from pydantic import ConfigDict, BaseModel
+from pydantic import BaseModel, ConfigDict, Field
+
+from sqlalchemy.inspection import inspect as sa_inspect
 
 from app import models
+from app.state_key import parse_state_key_column
 
 
 class State(Enum):
@@ -31,6 +34,16 @@ class State(Enum):
 
 class School(BaseModel):
     id: str
+    state_key: Optional[State] = Field(
+        default=None,
+        description=(
+            "ISO 3166-2:DE subdivision code without the DE- prefix (same vocabulary as the `state` "
+            "query filter). Stored in the database from the Land scraper that produced the row "
+            "(same code used when composing `id`); identifies which JedeSchule feed produced the row "
+            "(not coordinates). Aligns with pipeline-declared `state_key` for split-by-Land jobs. "
+            "Omitted when unset or not a known code."
+        ),
+    )
     name: str
     address: str
     address2: Optional[str] = None
@@ -52,12 +65,15 @@ class School(BaseModel):
 
     @staticmethod
     def from_db(db_entry: models.School) -> School:
-        if not db_entry.location:
-            return School.model_validate(db_entry)
-        shape = to_shape(db_entry.location)
-        school = School.model_validate(db_entry)
-        school.latitude = shape.y
-        school.longitude = shape.x
+        insp = sa_inspect(db_entry)
+        cols = {c.key: getattr(db_entry, c.key) for c in insp.mapper.column_attrs}
+        cols.pop("location", None)
+        cols["state_key"] = parse_state_key_column(cols.get("state_key"))
+        school = School.model_validate(cols)
+        if db_entry.location:
+            shape = to_shape(db_entry.location)
+            school.latitude = shape.y
+            school.longitude = shape.x
         return school
 
 
diff --git a/app/state_key.py b/app/state_key.py
new file mode 100644
index 0000000..5ebb152
--- /dev/null
+++ b/app/state_key.py
@@ -0,0 +1,23 @@
+"""Validate `schools.state_key` from the database (set by jedeschule-scraper per Land)."""
+
+from __future__ import annotations
+
+from typing import TYPE_CHECKING, Optional
+
+if TYPE_CHECKING:
+    from app.schemas import State
+
+
+def parse_state_key_column(raw: str | None) -> Optional[State]:
+    """Map stored ``state_key`` text to :class:`State`, or ``None`` if missing/invalid."""
+    from app.schemas import State as StateEnum
+
+    if raw is None:
+        return None
+    s = raw.strip()
+    if len(s) != 2:
+        return None
+    try:
+        return StateEnum(s)
+    except ValueError:
+        return None
diff --git a/test/factory.py b/test/factory.py
index 895b869..3bc7d49 100644
--- a/test/factory.py
+++ b/test/factory.py
@@ -16,6 +16,8 @@ def _get_state(n):
         return states[n % len(states)]
 
     id = factory.Sequence(lambda n: "{}-{}".format(SchoolFactory._get_state(n), n))
+    # Same Land code the jedeschule-scraper sets on each spider (matches id prefix).
+    state_key = factory.Sequence(lambda n: SchoolFactory._get_state(n))
     name = factory.Sequence(lambda n: 'School %d' % n)
     address = factory.Faker('address')
 
@@ -23,6 +25,7 @@ def _get_state(n):
 def get_full_school():
     return School(
         id="NW-112586",
+        state_key="NW",
         name="Städt. Gem. Grundschule - Primarstufe -",
         address="Pfälzer Str. 30-34",
         city="Köln",
diff --git a/test/test_api.py b/test/test_api.py
index a34376f..54cec91 100644
--- a/test/test_api.py
+++ b/test/test_api.py
@@ -10,6 +10,8 @@
 from app.main import app, get_db
 from app.database import Base
 from app.models import School
+from app.schemas import State
+from app.state_key import parse_state_key_column
 from test.factory import SchoolFactory, get_full_school
 
 engine = create_engine(os.environ.get("DATABASE_URL_TEST"))
@@ -43,6 +45,13 @@ def client() -> Generator:
         yield c
 
 
+def test_parse_state_key_column():
+    assert parse_state_key_column("NW") == State.NW
+    assert parse_state_key_column("XX") is None
+    assert parse_state_key_column(None) is None
+    assert parse_state_key_column("") is None
+
+
 class TestStats:
     def test_stats(self, client, db):
         ni_schools = [School(id=f"NI-{i}", update_timestamp=datetime(2025, 1, 1)) for i in range(10)]
@@ -176,6 +185,7 @@ def test_schools_json_default_without_raw(self, client, db):
         assert response.json() == [
             {
                 "id": "NW-112586",
+                "state_key": "NW",
                 "name": "Städt. Gem. Grundschule - Primarstufe -",
                 "address": "Pfälzer Str. 30-34",
                 "city": "Köln",
@@ -201,6 +211,7 @@ def test_schools_json_with_raw(self, client, db):
         assert response.json() == [
             {
                 "id": "NW-112586",
+                "state_key": "NW",
                 "name": "Städt. Gem. Grundschule - Primarstufe -",
                 "address": "Pfälzer Str. 30-34",
                 "city": "Köln",
@@ -244,6 +255,7 @@ def test_schools_json_exposes_lat_and_lon(self, client, db):
         # Arrange
         school = SchoolFactory(
             id=f"NW-100010",
+            state_key="NW",
             location="SRID=4326;POINT(6.897017373118707 50.94217152830834)",
             name="Gymnasium Claudia Agrippina Privat schule als priv.Ersatzsch. d. Sek.I u.II im Aufbau d. CAPS Privatschu gGmbH",
             address="Stolberger Str. 112",
@@ -258,6 +270,7 @@ def test_schools_json_exposes_lat_and_lon(self, client, db):
         # Assert
         assert response.json() == {
             "id": "NW-100010",
+            "state_key": "NW",
             "name": "Gymnasium Claudia Agrippina Privat schule als priv.Ersatzsch. d. Sek.I u.II im Aufbau d. CAPS Privatschu gGmbH",
             "address": "Stolberger Str. 112",
             "latitude": 50.94217152830834,
@@ -380,3 +393,23 @@ def test_get_single_no_result(self, client, db):
         # Assert
         assert response.status_code == 404
 
+    def test_school_malformed_id_omits_state_key(self, client, db):
+        db.add(SchoolFactory(id="XX-12345", name="Unknown prefix", state_key=None))
+        db.commit()
+
+        response = client.get("/schools/XX-12345")
+
+        assert response.status_code == 200
+        body = response.json()
+        assert body["id"] == "XX-12345"
+        assert "state_key" not in body
+
+    def test_school_id_without_hyphen_omits_state_key(self, client, db):
+        db.add(SchoolFactory(id="nohyphen", name="No dash", state_key=None))
+        db.commit()
+
+        response = client.get("/schools/nohyphen")
+
+        assert response.status_code == 200
+        assert "state_key" not in response.json()
+