20 C.F.R. § 404.405
The following provisions are savings clauses and describe exceptions to the rules concerning the maximum amount payable on an individual's earnings record in a month as described in § 404.403. The effect of a savings clause is to avoid lowering benefit amounts or to guarantee minimum increases to certain persons entitled on the earnings record of the insured individual when a statutory change has been made that would otherwise disadvantage them. The reduction described in § 404.403 does not apply in the following instances:
(n) Months after August 1972. The reduction described in § 404.403(a) shall not apply to benefits for months after August 1972 where two or more persons were entitled to benefits for August 1972 based upon the filing of an application in August 1972 or earlier and the total of such benefits was subject to reduction for the maximum under § 404.403 (or would have been subject to such reduction except for this paragraph) for January 1971. In such a case, maximum family benefits on the insured individual's earnings record for any month after August 1972 may not be less than the larger of:
(o) Months after December 1972. The reduction described in § 404.403 shall not apply to benefits for months after December 1972 in the following cases:
(1) In the case of a redetermination of widow's or widower's benefits, the reduction described in § 404.403 shall not apply if:
(ii) The total of benefits to which all persons are entitled for January 1973 is reduced (or would be reduced if deductions were not applicable) for the maximum under § 404.403.
In such case, the benefit of each person referred to in paragraph (o)(1)(i) of this section for months after December 1972 shall be no less than the amount it would have been if the widow's or widower's benefit had not been redetermined under the Social Security Amendments of 1972.
(2) In the case of entitlement to child's benefits based upon disability which began between ages 18 and 22 the reduction described in § 404.403 shall not apply if:
(iii) The total benefits to which all persons are entitled on that record for January 1973 is reduced (or would be reduced if deductions were not applicable) for the maximum under § 404.403.
In such case, the benefit of each person referred to in paragraph (o)(2)(i) of this section for months after December 1972 shall be no less than the amount it would have been if the person entitled to child's benefits based upon disability in the period from ages 18 to 22 were not so entitled.
(3) In the case of entitlement of certain surviving divorced mothers, the reduction described in § 404.403 shall not apply if:
(iii) The total of benefits to which all persons are entitled on that record for any month after December 1972 is reduced (or would be reduced if deductions were not applicable) for the maximum under § 404.403.
In such case, the benefit of each such person referred to in paragraph (o)(3)(i) of this section for months after December 1972 in which any person referred to in paragraph (o)(3)(ii) of this section is entitled shall be no less than it would have been if the person(s) referred to in paragraph (o)(3)(ii) of this section had not become entitled to benefits.
(p) Months after December 1973. The reduction described in § 404.403 shall not apply to benefits for months after December 1973 where two or more persons were entitled to monthly benefits for January 1971 or earlier based upon applications filed in January 1971 or earlier, and the total of such benefits was subject to reduction for the maximum under § 404.403 for January 1971 or earlier. In such a case, maximum family benefits payable on the insured individual's earnings record for any month after January 1971 may not be less than the larger of:
(q) Months after May 1978. The family maximum for months after May 1978 is figured for all beneficiaries just as it would have been if none of them had gotten a benefit increase because of the retirement credit if:
[32 FR 19159, Dec. 20, 1967, as amended at 40 FR 30814, July 23, 1975; 43 FR 8132, Feb. 28, 1978; 43 FR 29277, July 7, 1978; 48 FR 46148, Oct. 11, 1983]