diff --git a/changelog.d/415.added.md b/changelog.d/415.added.md
new file mode 100644
index 00000000..ba0680e8
--- /dev/null
+++ b/changelog.d/415.added.md
@@ -0,0 +1 @@
+`managed_microsimulation` and `resolve_managed_dataset_reference` now accept a local filesystem path to a dataset when `allow_unmanaged=True`. Local build-and-score pipelines can run their own Stage-output artifacts (H5 files that are not part of any release manifest) through the managed wrapper, instead of constructing country-package simulations directly. Passing a local path without `allow_unmanaged=True` raises an actionable error rather than the generic "Unknown dataset" message.
diff --git a/src/policyengine/provenance/manifest.py b/src/policyengine/provenance/manifest.py
index 3d44a11e..065c4e85 100644
--- a/src/policyengine/provenance/manifest.py
+++ b/src/policyengine/provenance/manifest.py
@@ -467,9 +467,12 @@ def resolve_managed_dataset_reference(
 
     - omit `dataset` to use the certified default dataset for the bundle
     - pass a logical dataset name present in the bundled/data-release manifests
+    - pass a local filesystem path with `allow_unmanaged=True` to run on a
+      build artifact the caller owns (e.g. a downstream pipeline's Stage-output
+      H5 that is not part of any release manifest)
 
-    Direct URLs or raw Hugging Face references are treated as unmanaged unless
-    `allow_unmanaged=True` is set explicitly.
+    Direct URLs, raw Hugging Face references, and local filesystem paths are
+    treated as unmanaged unless `allow_unmanaged=True` is set explicitly.
     """
 
     manifest = get_release_manifest(country_id)
@@ -488,7 +491,24 @@ def resolve_managed_dataset_reference(
             "bypass bundle enforcement."
         )
 
-    return resolve_dataset_reference(country_id, dataset)
+    try:
+        return resolve_dataset_reference(country_id, dataset)
+    except ValueError:
+        # Not a managed dataset name. A local build artifact (e.g. a
+        # Stage-output H5 from a downstream pipeline) is unmanaged but
+        # legitimate; accept it under the same explicit opt-in as remote URIs
+        # so local build-and-score workflows need not bypass this wrapper.
+        candidate = Path(dataset).expanduser()
+        if candidate.is_file():
+            if allow_unmanaged:
+                return str(candidate)
+            raise ValueError(
+                f"Dataset {dataset!r} is a local file outside the "
+                "policyengine.py release bundle. Pass `allow_unmanaged=True` to "
+                "run a simulation on a local build artifact; its model-version "
+                "pairing is then the caller's responsibility."
+            ) from None
+        raise
 
 
 def resolve_local_managed_dataset_source(
diff --git a/tests/test_release_manifests.py b/tests/test_release_manifests.py
index e9de59f4..d025a0c1 100644
--- a/tests/test_release_manifests.py
+++ b/tests/test_release_manifests.py
@@ -212,6 +212,35 @@ def test__given_explicit_uri__then_managed_resolution_requires_opt_in(self):
             == dataset
         )
 
+    def test__given_local_path__then_managed_resolution_requires_opt_in(self, tmp_path):
+        local_dataset = tmp_path / "2026.h5"
+        local_dataset.write_bytes(b"")
+
+        try:
+            resolve_managed_dataset_reference("us", str(local_dataset))
+        except ValueError as error:
+            assert "local file outside the policyengine.py release bundle" in str(error)
+        else:
+            raise AssertionError("Expected local dataset path to require opt-in")
+
+    def test__given_local_path_with_opt_in__then_resolves_to_that_path(self, tmp_path):
+        local_dataset = tmp_path / "2026.h5"
+        local_dataset.write_bytes(b"")
+
+        assert resolve_managed_dataset_reference(
+            "us",
+            str(local_dataset),
+            allow_unmanaged=True,
+        ) == str(local_dataset)
+
+    def test__given_unknown_dataset_name__then_raises_unknown_dataset(self):
+        try:
+            resolve_managed_dataset_reference("us", "not_a_real_dataset_name")
+        except ValueError as error:
+            assert "Unknown dataset" in str(error)
+        else:
+            raise AssertionError("Expected unknown dataset name to be rejected")
+
     def test__given_versioned_dataset_url__then_logical_name_drops_version(self):
         dataset = "hf://policyengine/policyengine-us-data/enhanced_cps_2024.h5@1.73.0"