N.Y. Comp. Codes R. & Regs. tit. 18 § 398-11.3
An underpayment is the difference between the amount of SSP benefits that a SSP recipient was eligible to receive while currently receiving SSP benefits and in active pay status for federal SSI benefits as defined in section 398-2.1 of this Part, with an eligible federal payment status code as defined in section 398-2.1 of this Part as of such time that the federal SSA electronic data file, containing such individual's or couple's relevant SSI eligibility determination is transmitted to NYS via the SDX and the lesser amount of SSP benefits actually issued to or on behalf of the SSP or SSPNA recipient. When the Office determines that an underpayment has occurred, appropriate corrective action will be taken. Underpayments may only be issued to currently active SSP recipients. Underpayments will be limited to the month the change was reported and three prior consecutive months when due to untimely reporting, by a recipient, as defined in section 398-2.1 of this Part. SSP underpayments may not be issued to, or assigned on behalf of, deceased individuals, their payees, relatives, heirs, estates or on behalf of any debt, including any debt owing to a congregate care facility where such individual may have been provided room and board, or any other private or public entities to whom the deceased SSP recipients may owe payment.
N.Y. Comp. Codes R. & Regs. Tit. 18 § 398-11.3