diff --git a/data/data-pipeline/data_pipeline/etl/score/constants.py b/data/data-pipeline/data_pipeline/etl/score/constants.py
index 46adab52f..410d194c4 100644
--- a/data/data-pipeline/data_pipeline/etl/score/constants.py
+++ b/data/data-pipeline/data_pipeline/etl/score/constants.py
@@ -381,8 +381,6 @@
     field_names.PERCENT_AGE_OVER_64: "AGE_OLD",
     field_names.COUNT_OF_TRIBAL_AREAS_IN_TRACT: "TA_COUNT",
     field_names.PERCENT_OF_TRIBAL_AREA_IN_TRACT: "TA_PERC",
-    
-
 }
 
 # columns to round floats to 2 decimals
@@ -456,5 +454,5 @@
     field_names.ELIGIBLE_FUDS_BINARY_FIELD_NAME,
     field_names.AML_BOOLEAN,
     field_names.HISTORIC_REDLINING_SCORE_EXCEEDED,
-    field_names.PERCENT_OF_TRIBAL_AREA_IN_TRACT
+    field_names.PERCENT_OF_TRIBAL_AREA_IN_TRACT,
 ]
diff --git a/data/data-pipeline/data_pipeline/etl/score/etl_score.py b/data/data-pipeline/data_pipeline/etl/score/etl_score.py
index b0fc3b4d8..7ee7b18a1 100644
--- a/data/data-pipeline/data_pipeline/etl/score/etl_score.py
+++ b/data/data-pipeline/data_pipeline/etl/score/etl_score.py
@@ -634,8 +634,24 @@ class ReversePercentile:
             ]
         ].mean(axis=1, skipna=True)
 
+        # For AS, MP, GU, and VI, backfill data from the 2010 census where we have it
+        df_copy = self._backfill_island_data(df_copy)
+
         return df_copy
 
+    @staticmethod
+    def _backfill_island_data(df: pd.DataFrame) -> pd.DataFrame:
+        logger.info("Backfilling island data")
+        island_index = (
+            df[field_names.GEOID_TRACT_FIELD]
+            .str[:2]
+            .isin(constants.TILES_ISLAND_AREA_FIPS_CODES)
+        )
+        df.loc[island_index, field_names.TOTAL_POP_FIELD] = df.loc[
+            island_index, field_names.COMBINED_CENSUS_TOTAL_POPULATION_2010
+        ]
+        return df
+
     def transform(self) -> None:
         logger.info("Transforming Score Data")
 
diff --git a/data/data-pipeline/data_pipeline/tests/score/test_output.py b/data/data-pipeline/data_pipeline/tests/score/test_output.py
index f10e6f71c..d6a5cb1a0 100644
--- a/data/data-pipeline/data_pipeline/tests/score/test_output.py
+++ b/data/data-pipeline/data_pipeline/tests/score/test_output.py
@@ -7,6 +7,7 @@
 import numpy as np
 from data_pipeline.score import field_names
 from data_pipeline.score.field_names import GEOID_TRACT_FIELD
+from data_pipeline.etl.score.constants import TILES_ISLAND_AREA_FIPS_CODES
 from .fixtures import (
     final_score_df,
     ejscreen_df,
@@ -287,7 +288,24 @@ def test_data_sources(
 
         # Make sure we have NAs for any tracts in the final data that aren't
         # included in the data source
-        assert np.all(df[df.MERGE == "left_only"][final_columns].isna())
+        has_additional_non_null_tracts = not np.all(
+            df[df.MERGE == "left_only"][final_columns].isna()
+        )
+        if has_additional_non_null_tracts:
+            # We backfill island areas with data from the 2010 census, so if THOSE tracts
+            # have data beyond the data source, that's to be expected and is fine to pass.
+            # If some other state or territory does though, this should fail
+            left_only = df.loc[(df.MERGE == "left_only")]
+            left_only_has_value = left_only.loc[
+                ~df[final_columns].isna().all(axis=1)
+            ]
+            fips_with_values = set(
+                left_only_has_value[field_names.GEOID_TRACT_FIELD].str[0:2]
+            )
+            non_island_fips_codes = fips_with_values.difference(
+                TILES_ISLAND_AREA_FIPS_CODES
+            )
+            assert not non_island_fips_codes
 
         # Make sure the datasource doesn't have a ton of unmatched tracts, implying it
         # has moved to 2020 tracts
diff --git a/data/data-pipeline/data_pipeline/tests/sources/eamlis/test_etl.py b/data/data-pipeline/data_pipeline/tests/sources/eamlis/test_etl.py
index 37b15f650..09275de2e 100644
--- a/data/data-pipeline/data_pipeline/tests/sources/eamlis/test_etl.py
+++ b/data/data-pipeline/data_pipeline/tests/sources/eamlis/test_etl.py
@@ -156,4 +156,4 @@ def test_tract_id_lengths(self, mock_etl, mock_paths):
             "data_pipeline.etl.sources.eamlis.etl.add_tracts_for_geometries",
             new=_fake_add_tracts_for_geometries,
         ):
-            super().test_tract_id_lengths(mock_etl, mock_paths)
\ No newline at end of file
+            super().test_tract_id_lengths(mock_etl, mock_paths)