In the case of an individual whose primary insurance amount has been computed or recomputed under section 415(a)(1) or (4) of this title, or section 415(d) of this title , as in effect after December 1978, the total monthly benefits to which beneficiaries may be entitled under section 402 or 423 of this title for a month on the basis of the wages and self-employment income of such individual shall, except as provided by paragraphs (3) and (6) (but prior to any increases resulting from the application of paragraph (2)(A)(ii)(III) of section 415(i) of this title ), be reduced as necessary so as not to exceed—

(A) 150 percent of such individual’s primary insurance amount to the extent that it does not exceed the amount established with respect to this subparagraph by paragraph (2),

(B) 272 percent of such individual’s primary insurance amount to the extent that it exceeds the amount established with respect to subparagraph (A) but does not exceed the amount established with respect to this subparagraph by paragraph (2),

(C) 134 percent of such individual’s primary insurance amount to the extent that it exceeds the amount established with respect to subparagraph (B) but does not exceed the amount established with respect to this subparagraph by paragraph (2), and

(D) 175 percent of such individual’s primary insurance amount to the extent that it exceeds the amount established with respect to subparagraph (C).

Any such amount that is not a multiple of $0.10 shall be decreased to the next lower multiple of $0.10.