Increase in old-age insurance benefit amounts on account of delayed retirement

The amount of an old-age insurance benefit (other than a benefit based on a primary insurance amount determined under section 415(a)(3) of this title as in effect in December 1978 or section 415(a)(1)(C)(i) of this title as in effect thereafter) which is payable without regard to this subsection to an individual shall be increased by—

(A) the applicable percentage (as determined under paragraph (6)) of such amount, multiplied by

(B) the number (if any) of the increment months for such individual.

For purposes of this subsection, the number of increment months for any individual shall be a number equal to the total number of the months—

(A) which have elapsed after the month before the month in which such individual attained retirement age (as defined in section 416( l ) of this title) or (if later) December 1970 and prior to the month in which such individual attained age 70, and

(B) with respect to which— (i) such individual was a fully insured individual (as defined in section 414(a) of this title ), (ii) such individual either was not entitled to an old-age insurance benefit or, if so entitled, did not receive benefits pursuant to a request under subsection (z) by such individual that benefits not be paid, and (iii) such individual was not subject to a penalty imposed under section 1320a–8a of this title .

For purposes of applying the provisions of paragraph (1), a determination shall be made under paragraph (2) for each year, beginning with 1972, of the total number of an individual’s increment months through the year for which the determination is made and the total so determined shall be applicable to such individual’s old-age insurance benefits beginning with benefits for January of the year following the year for which such determination is made; except that the total number applicable in the case of an individual who attains age 70 after 1972 shall be determined through the month before the month in which he attains such age and shall be applicable to his old-age insurance benefit beginning with the month in which he attains such age.

If an individual’s primary insurance amount is determined under paragraph (3) of section 415(a) of this title as in effect in December 1978, or section 415(a)(1)(C)(i) of this title as in effect thereafter, and, as a result of this subsection, he would be entitled to a higher old-age insurance benefit if his primary insurance amount were determined under section 415(a) of this title (whether before, in, or after December 1978) without regard to such paragraph, such individual’s old-age insurance benefit based upon his primary insurance amount determined under such paragraph shall be increased by an amount equal to the difference between such benefit and the benefit to which he would be entitled if his primary insurance amount were determined under such section without regard to such paragraph.

For purposes of paragraph (1)(A), the “applicable percentage” is—

(A) 1 ⁄ 12 of 1 percent in the case of an individual who first becomes eligible for an old-age insurance benefit in any calendar year before 1979;

(B) ¼ of 1 percent in the case of an individual who first becomes eligible for an old-age insurance benefit in any calendar year after 1978 and before 1987;

(C) in the case of an individual who first becomes eligible for an old-age insurance benefit in a calendar year after 1986 and before 2005, a percentage equal to the applicable percentage in effect under this paragraph for persons who first became eligible for an old-age insurance benefit in the preceding calendar year (as increased pursuant to this subparagraph), plus 1 ⁄ 24 of 1 percent if the calendar year in which that particular individual first becomes eligible for such benefit is not evenly divisible by 2; and

(D) ⅔ of 1 percent in the case of an individual who first becomes eligible for an old-age insurance benefit in a calendar year after 2004.