diff --git a/src/microplex_us/pipelines/us.py b/src/microplex_us/pipelines/us.py
index 2f05f50..d1cf379 100644
--- a/src/microplex_us/pipelines/us.py
+++ b/src/microplex_us/pipelines/us.py
@@ -195,6 +195,7 @@
     "self_employment_income_would_be_qualified",
 )
 
+DEFAULT_ACA_TAKEUP_RATE = 0.672
 DEFAULT_SNAP_TAKEUP_RATE = 0.82
 
 
@@ -222,10 +223,12 @@ def _policyengine_us_data_seeded_rng(
 
 
 def _load_policyengine_us_data_takeup_rate(variable_name: str, year: int) -> float:
-    """Load an eCPS take-up rate, with a SNAP fallback for non-PE-data envs."""
+    """Load an eCPS take-up rate, with scalar fallbacks for non-PE-data envs."""
     try:
         from policyengine_us_data.parameters import load_take_up_rate
     except ImportError:
+        if variable_name == "aca":
+            return DEFAULT_ACA_TAKEUP_RATE
         if variable_name == "snap":
             return DEFAULT_SNAP_TAKEUP_RATE
         raise
@@ -4750,6 +4753,7 @@ def build_policyengine_entity_tables(
 
         households = self._build_policyengine_households(persons)
         tax_units, persons = self._build_policyengine_tax_units(persons)
+        tax_units = self._attach_policyengine_aca_takeup(tax_units)
         persons = self._construct_aotc_eligibility_inputs(persons)
         persons = self._assign_family_and_spm_units(persons)
         families = self._collapse_group_table(persons, "family_id")
@@ -8450,24 +8454,33 @@ def _infer_policyengine_aca_takeup_for_tax_unit(
                 .ne(0.0)
                 .any()
             )
-        marketplace_columns = (
-            "has_marketplace_health_coverage",
-            "has_marketplace_health_coverage_at_interview",
-            "reported_has_marketplace_health_coverage_at_interview",
-            "reported_has_subsidized_marketplace_health_coverage_at_interview",
-            "reported_has_unsubsidized_marketplace_health_coverage_at_interview",
-        )
-        observed = [
-            column for column in marketplace_columns if column in unit_persons.columns
-        ]
-        if not observed:
-            return None
-        marketplace = pd.Series(False, index=unit_persons.index, dtype=bool)
-        for column in observed:
-            marketplace |= (
-                pd.to_numeric(unit_persons[column], errors="coerce").fillna(0.0).ne(0.0)
+        return None
+
+    def _attach_policyengine_aca_takeup(
+        self,
+        tax_units: pd.DataFrame,
+    ) -> pd.DataFrame:
+        """Attach eCPS-style ACA take-up input before PE materialization."""
+        result = tax_units.copy()
+        column = "takes_up_aca_if_eligible"
+        if column in result.columns:
+            result[column] = (
+                pd.to_numeric(result[column], errors="coerce")
+                .fillna(0.0)
+                .ne(0.0)
+                .astype(bool)
             )
-        return bool(marketplace.any())
+            return result
+
+        year = int(
+            self.config.policyengine_dataset_year
+            or self.config.policyengine_target_period
+            or 2024
+        )
+        rate = _load_policyengine_us_data_takeup_rate("aca", year)
+        rng = _policyengine_us_data_seeded_rng(column)
+        result[column] = rng.random(len(result)) < rate
+        return result
 
     def _split_preserved_tax_unit_members(
         self,
diff --git a/tests/pipelines/test_us.py b/tests/pipelines/test_us.py
index 12d6baf..3d0ebc3 100644
--- a/tests/pipelines/test_us.py
+++ b/tests/pipelines/test_us.py
@@ -1056,6 +1056,7 @@ def fake_load_takeup_rate(variable_name: str, year: int) -> float:
                 "age": [45, 12, 70],
                 "income": [60_000.0, 0.0, 25_000.0],
                 "relationship_to_head": [0, 2, 0],
+                "takes_up_aca_if_eligible": [True, True, True],
             }
         )
 
@@ -1257,7 +1258,21 @@ def test_build_policyengine_entity_tables_derives_tax_input_columns(self):
         assert person_rows["medicaid_enrolled"].tolist() == [False, True]
         assert person_rows["state_income_tax_reported"].tolist() == [400.0, 50.0]
 
-    def test_build_policyengine_entity_tables_adds_deterministic_aca_takeup(self):
+    def test_build_policyengine_entity_tables_adds_deterministic_aca_takeup(
+        self,
+        monkeypatch,
+    ):
+        calls: list[tuple[str, int]] = []
+
+        def fake_load_takeup_rate(variable_name: str, year: int) -> float:
+            calls.append((variable_name, year))
+            return 0.0
+
+        monkeypatch.setattr(
+            us_pipeline_module,
+            "_load_policyengine_us_data_takeup_rate",
+            fake_load_takeup_rate,
+        )
         pipeline = USMicroplexPipeline(
             USMicroplexBuildConfig(policyengine_dataset_year=2024)
         )
@@ -1274,13 +1289,19 @@ def test_build_policyengine_entity_tables_adds_deterministic_aca_takeup(self):
                 "state_fips": [6, 12, 48],
                 "tenure": [1, 1, 1],
                 "has_marketplace_health_coverage": [True, False, True],
+                "takes_up_snap_if_eligible": [True, True, True],
             }
         )
 
         tables = pipeline.build_policyengine_entity_tables(population)
 
         tax_units = tables.tax_units.sort_values("household_id").reset_index(drop=True)
-        assert tax_units["takes_up_aca_if_eligible"].tolist() == [True, False, True]
+        assert calls == [("aca", 2024)]
+        assert tax_units["takes_up_aca_if_eligible"].tolist() == [
+            False,
+            False,
+            False,
+        ]
 
     def test_build_policyengine_entity_tables_preserves_explicit_aca_takeup(self):
         pipeline = USMicroplexPipeline(