20 CFR § 404.338 - Widow's and widower's benefits amounts.
(a) Your monthly benefit is equal to the insured person's primary insurance amount. If the insured person dies before reaching age 62 and you are first eligible after 1984, we may compute a special primary insurance amount to determine the amount of the monthly benefit (see § 404.212(b)).
(b) We may increase your monthly benefit amount if the insured person delays filing for benefits or requests voluntary suspension of benefits, and thereby earns delayed retirement credit (see § 404.313), and/or works before the year 2000 after reaching full retirement age (as defined in § 404.409(a)). The amount of your monthly benefit may change as explained in § 404.304.
(c) Your monthly benefit will be reduced if the insured person chooses to receive old-age benefits before reaching full retirement age. If so, your benefit will be reduced to the amount the insured person would be receiving if alive, or 82 1/2 percent of his or her primary insurance amount, whichever is larger.
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