20 CFR § 320.9 - Notice of erroneous benefit payment.
(a) Content of notice. When an adjudicating office determines that benefits were paid erroneously, that office shall issue to the claimant a notice of the amount of the erroneous payment and the basis for the determination. The notice shall include a statement telling the claimant of his or her right to request reconsideration of the determination, of the provisions for waiver and of his or her right to request waiver.
(b) Communication of notice of erroneous payment. When the adjudicating office mails the erroneous payment notice to the claimant's address of record, it shall be considered that notice of the erroneous payment has been communicated to the claimant on the date of mailing such notice. If the adjudicating office has been notified that a claimant has an attorney or other representative helping him or her with the claim, a copy of the erroneous payment notice shall be sent to the attorney or such other representative.