diff --git a/db/migration/000028_move_sev_4_members_into_sev_3.up.sql b/db/migration/000028_move_sev_4_members_into_sev_3.up.sql
new file mode 100644
index 0000000..f6a3c04
--- /dev/null
+++ b/db/migration/000028_move_sev_4_members_into_sev_3.up.sql
@@ -0,0 +1,27 @@
+BEGIN;
+
+-- Delete existing Sev-3 mappings for users in Sev-4
+DELETE
+FROM team_user_severity tus
+    USING team_severity ts_4, team_severity ts_3
+WHERE tus.team_severity = ts_3.id
+  AND ts_3.severity_id = 4
+  AND ts_4.severity_id = 5
+  AND ts_4.team_id = ts_3.team_id
+  AND tus.team_user IN (SELECT tus.team_user
+                        FROM team_user_severity tus
+                                 JOIN team_severity ts ON tus.team_severity = ts.id
+                        WHERE ts.severity_id = 5);
+
+
+-- Insert new Sev-3 mappings for users in Sev-4
+INSERT INTO team_user_severity (team_user, team_severity)
+SELECT tus.team_user, ts_3.id
+FROM team_user_severity tus
+         JOIN team_severity ts_4 ON tus.team_severity = ts_4.id
+         JOIN team_severity ts_3 ON ts_3.team_id = ts_4.team_id
+WHERE ts_4.severity_id = 5
+  AND ts_3.severity_id = 4
+ON CONFLICT DO NOTHING;
+
+COMMIT;
\ No newline at end of file