; and (iv) 15 percent (reduced as provided in subparagraph (C)) of the individual's average indexed monthly earnings to the extent that such earnings exceed the amount established for purposes of paragraph (1)(A)(ii) by paragraph (1)(B). (B) (i) For purposes of subparagraph (A)(ii), the amount established under this subparagraph for calendar year 2025 shall be the level of average indexed monthly earnings determined by the Chief Actuary of the Social Security Administration under clause (ii) as being at the 40th percentile for the period of calendar years 2016 through 2018. (ii) For purposes of clause (i), the average indexed monthly earnings for the period of calendar years 2016 through 2018 shall be determined by— (I) determining the average indexed monthly earnings for each individual who initially became eligible for old-age insurance benefits or who died (before becoming eligible for such benefits) during such period, except that in determining such average indexed monthly earnings under subsection (b), subsection (b)(3)(A)(ii)(I) shall be applied by substituting calendar year 2013 for the second calendar year described in such subsection; and (II) multiplying the amount determined for each individual under subclause (I) by the quotient obtained by dividing the national average wage index (as defined in section 209(k)(1)) for the calendar year 2025 by such index for the calendar year 2013. (iii) For purposes of subparagraph (A)(ii), the amount established under this subparagraph for any calendar year after 2027 shall be equal to the product of the amount in effect under clause (i) with respect to calendar year 2027 and the quotient obtained by dividing— (I) the national average wage index (as defined in section 209(k)(1)) for the second calendar year preceding the calendar year for which the determination is being made