20 CFR §404.1299

1. (a)Overpayments. Payment of amounts due to a State required as the result of a final judgment of the court shall be adjusted under §§ 404.1271 and 404.1272.
2. (b)Underpayments. Wage reports and contribution returns required as the result of a final judgment of the court shall be filed under §§ 404.1237-404.1251. We will assess interest under § 404.1265 where, based upon a final judgment of the court, contributions are due from a State because the amount of contributions assessed was not paid by the State or the State had used an allowance of a credit or refund of an overpayment.