34 CFR 34.28: Refunds of amounts collected in error.

(a) If a hearing official determines under §§ 34.16 and 34.17 that a person does not owe the debt described in our notice or that an administrative wage garnishment under this part was barred by law at the time of the collection action, we promptly refund any amount collected by means of this garnishment.

(b) Unless required by Federal law or contract, we do not pay interest on a refund.