diff --git a/changelog.d/837.fixed b/changelog.d/837.fixed
new file mode 100644
index 000000000..2a2b470f8
--- /dev/null
+++ b/changelog.d/837.fixed
@@ -0,0 +1 @@
+Impute unavailable CPS prior-year wage and self-employment income instead of emitting sentinel values.
diff --git a/policyengine_us_data/datasets/cps/cps.py b/policyengine_us_data/datasets/cps/cps.py
index d12ba7eef..94e57209c 100644
--- a/policyengine_us_data/datasets/cps/cps.py
+++ b/policyengine_us_data/datasets/cps/cps.py
@@ -1108,6 +1108,8 @@ def add_previous_year_income(self, cps: h5py.File) -> None:
         )
         return
 
+    prior_year_income_sentinels = {-1, -9999}
+
     with (
         _open_dataset_read_only(self.raw_cps) as cps_current_year_data,
         _open_dataset_read_only(self.previous_year_raw_cps) as cps_previous_year_data,
@@ -1137,19 +1139,48 @@ def add_previous_year_income(self, cps: h5py.File) -> None:
 
         joined_data = cps_current_year.join(previous_year_data)[
             [
+                "WSAL_VAL",
+                "SEMP_VAL",
                 "employment_income_last_year",
                 "self_employment_income_last_year",
-                "I_ERNVAL",
-                "I_SEVAL",
             ]
-        ]
+        ].rename(
+            {
+                "WSAL_VAL": "current_year_employment_income",
+                "SEMP_VAL": "current_year_self_employment_income",
+            },
+            axis=1,
+        )
+
+    invalid_previous_year_income = joined_data.employment_income_last_year.isin(
+        prior_year_income_sentinels
+    ) | joined_data.self_employment_income_last_year.isin(prior_year_income_sentinels)
+    joined_data.loc[
+        invalid_previous_year_income,
+        ["employment_income_last_year", "self_employment_income_last_year"],
+    ] = np.nan
+    joined_data.loc[
+        joined_data.current_year_employment_income.isin(prior_year_income_sentinels),
+        "current_year_employment_income",
+    ] = np.nan
+    joined_data.loc[
+        joined_data.current_year_self_employment_income.isin(
+            prior_year_income_sentinels
+        ),
+        "current_year_self_employment_income",
+    ] = np.nan
+
     joined_data["previous_year_income_available"] = (
         ~joined_data.employment_income_last_year.isna()
         & ~joined_data.self_employment_income_last_year.isna()
-        & (joined_data.I_ERNVAL == 0)
-        & (joined_data.I_SEVAL == 0)
     )
-    joined_data = joined_data.fillna(-1).drop(["I_ERNVAL", "I_SEVAL"], axis=1)
+    joined_data["employment_income_last_year"] = joined_data[
+        "employment_income_last_year"
+    ].fillna(joined_data["current_year_employment_income"])
+    joined_data["self_employment_income_last_year"] = joined_data[
+        "self_employment_income_last_year"
+    ].fillna(joined_data["current_year_self_employment_income"])
+    joined_data = joined_data.fillna(0)
 
     # CPS already ordered by PERIDNUM, so the join wouldn't change the order.
     cps["employment_income_last_year"] = joined_data[
diff --git a/tests/unit/datasets/test_cps_file_handles.py b/tests/unit/datasets/test_cps_file_handles.py
index db5add17f..62eaeeec7 100644
--- a/tests/unit/datasets/test_cps_file_handles.py
+++ b/tests/unit/datasets/test_cps_file_handles.py
@@ -42,6 +42,8 @@ def test_add_previous_year_income_closes_raw_cps_handles():
     current_person = pd.DataFrame(
         {
             "PERIDNUM": [10, 20],
+            "WSAL_VAL": [1_100, 2_100],
+            "SEMP_VAL": [110, 210],
             "I_ERNVAL": [0, 0],
             "I_SEVAL": [0, 0],
         }
@@ -79,6 +81,56 @@ def test_add_previous_year_income_closes_raw_cps_handles():
     assert previous_store.closed is True
 
 
+def test_add_previous_year_income_imputes_unavailable_rows():
+    current_person = pd.DataFrame(
+        {
+            "PERIDNUM": [10, 20, 30, 40, 50],
+            "WSAL_VAL": [1_100, 2_100, 3_100, 4_100, -1],
+            "SEMP_VAL": [110, 210, 310, 410, -9999],
+            "I_ERNVAL": [0, 0, 0, 0, 0],
+            "I_SEVAL": [0, 0, 0, 0, 0],
+        }
+    )
+    previous_person = pd.DataFrame(
+        {
+            "PERIDNUM": [10, 20, 30],
+            "WSAL_VAL": [1_000, 2_000, -9999],
+            "SEMP_VAL": [100, -1, 300],
+            "I_ERNVAL": [0, 0, 0],
+            "I_SEVAL": [0, 0, 0],
+        }
+    )
+
+    current_store = _FakeStore(current_person)
+    previous_store = _FakeStore(previous_person)
+
+    current_dataset = type("CurrentDataset", (_FakeDataset,), {"store": current_store})
+    previous_dataset = type(
+        "PreviousDataset", (_FakeDataset,), {"store": previous_store}
+    )
+
+    holder = SimpleNamespace(
+        raw_cps=current_dataset,
+        previous_year_raw_cps=previous_dataset,
+    )
+    cps = {}
+
+    add_previous_year_income(holder, cps)
+
+    np.testing.assert_array_equal(
+        cps["employment_income_last_year"],
+        [1_000, 2_100, 3_100, 4_100, 0],
+    )
+    np.testing.assert_array_equal(
+        cps["self_employment_income_last_year"],
+        [100, 210, 310, 410, 0],
+    )
+    np.testing.assert_array_equal(
+        cps["previous_year_income_available"],
+        [True, False, False, False, False],
+    )
+
+
 def test_add_previous_year_income_opens_hdfstores_read_only(tmp_path, monkeypatch):
     current_path = tmp_path / "current.h5"
     previous_path = tmp_path / "previous.h5"
@@ -87,6 +139,8 @@ def test_add_previous_year_income_opens_hdfstores_read_only(tmp_path, monkeypatc
         store["person"] = pd.DataFrame(
             {
                 "PERIDNUM": [10, 20],
+                "WSAL_VAL": [1_100, 2_100],
+                "SEMP_VAL": [110, 210],
                 "I_ERNVAL": [0, 0],
                 "I_SEVAL": [0, 0],
             }