diff --git a/src/main/resources/db/migration/V006_002__migrate_sample_ou_ids.sql b/src/main/resources/db/migration/V006_002__migrate_sample_ou_ids.sql
new file mode 100644
index 00000000..e944c439
--- /dev/null
+++ b/src/main/resources/db/migration/V006_002__migrate_sample_ou_ids.sql
@@ -0,0 +1,27 @@
+WITH
+    samples_and_bi_ou_ids AS (
+--      Look for samples that have obsUnitIDs and keep ids in hand for next query
+        SELECT
+            id as sample_id,
+            additional_info ->> 'obsUnitID' AS bi_ou_id
+FROM sample
+WHERE additional_info ? 'obsUnitID'
+    ),
+    ou_ids_matched_on_samples AS (
+--      Now match the bi-generated exref ou ids to ex refs ids, and keep samples ids for matching in update
+SELECT
+    ou.id AS ou_id,
+    samples_and_bi_ou_ids.sample_id
+FROM observation_unit ou
+    JOIN observation_unit_external_references ouex ON ou.id = ouex.observation_unit_entity_id
+    JOIN external_reference ex ON ouex.external_references_id = ex.id
+    JOIN samples_and_bi_ou_ids ON ex.external_reference_id = samples_and_bi_ou_ids.bi_ou_id
+    )
+UPDATE sample
+SET additional_info = jsonb_set(
+        additional_info,
+        '{obsUnitID}',
+        to_jsonb(mos.ou_id)
+                      )
+    FROM ou_ids_matched_on_samples mos
+WHERE id = mos.sample_id
\ No newline at end of file