20 C.F.R. § 404.458
Notwithstanding the provisions described in §§ 404.415 , 404.417 , 404.421 , 404.451 , and 404.453 about the amount of the deduction to be imposed for a month, no such deduction is imposed for a month when the benefits payable for that month to all persons entitled to benefits on the same earnings record and living in the same household remain equal to the maximum benefits payable to them on that earnings record. Where making such deductions and increasing the benefits to others in the household (for the month in which the deduction event occurred) would give members of the household less than the maximum (as determined under § 404.404 ) payable to them, the amount of deduction imposed is reduced to the difference between the maximum amount of benefits payable to them and the total amount which would have been paid if the benefits of members of the household not subject to deductions were increased for that month. The individual subject to the deduction for such month may be paid the difference between the deduction so reduced and his benefit as adjusted under § 404.403 (without application of § 404.402(a) ). All other persons in the household are paid, for such month, their benefits as adjusted under § 404.403 without application of § 404.402(a) .
20 C.F.R. §404.458