Subject to paragraph (9), if the first month for which an individual is entitled to an old-age, wife’s, husband’s, widow’s, or widower’s insurance benefit is a month before the month in which such individual attains retirement age, the amount of such benefit for such month and for any subsequent month shall, subject to the succeeding paragraphs of this subsection, be reduced by—

(A) 5 ⁄ 9 of 1 percent of such amount if such benefit is an old-age insurance benefit, 25 ⁄ 36 of 1 percent of such amount if such benefit is a wife’s or husband’s insurance benefit, or 19 ⁄ 40 of 1 percent of such amount if such benefit is a widow’s or widower’s insurance benefit, multiplied by

(B) (i) the number of months in the reduction period for such benefit (determined under paragraph (6)), if such benefit is for a month before the month in which such individual attains retirement age, or (ii) if less, the number of such months in the adjusted reduction period for such benefit (determined under paragraph (7)), if such benefit is (I) for the month in which such individual attains age 62, or (II) for the month in which such individual attains retirement age.