For purposes of subparagraph (A), the term “delinquent amount” means an amount—
(i)#
in excess of the correct amount of payment under this subchapter;
(ii)#
paid to a person after such person has attained 18 years of age; and
(iii)#
determined by the Commissioner of Social Security, under regulations, to be otherwise unrecoverable under this section after such person ceases to be a beneficiary under this subchapter.