of a head of household (as defined in section 2(b)), and (III) $200,000, in any other case. (iii) Applicable taxable year The term applicable taxable year means, with respect to any taxable year for which the credit under this section is determined— (I) such taxable year, or (II) if the taxpayer elects the application of this subclause (at such time and in such form and manner as the Secretary may provide), the preceding taxable year or the second preceding taxable year (as specified in such election). (iv) Modified adjusted gross income The term modified adjusted gross income means adjusted gross income increased by any amount excluded from gross income under section 911, 931, or 933. (3) Inflation adjustments (A) Monthly specified child allowance In the case of any month beginning after December 31, 2023, the $250 amount in paragraph (1)(A) shall be increased by an amount equal to— (i) such dollar amount, multiplied by— (ii) the percentage (if any) by which— (I) the CPI (as defined in section 1(f)(4)) for the calendar year preceding the calendar year in which such month begins, exceeds (II) the CPI (as so defined) for calendar year 2020. (B) Initial threshold amount In the case of any taxable year beginning after December 31, 2023, the dollar amounts in subclauses (I) and (III) of paragraph (2)(D)(i) shall each be increased by an amount equal to— (i) such dollar amount, multiplied by (ii) the percentage (if any) which would be determined under subparagraph (A)(ii) if subclause (II) thereof were applied by substituting 2022 for 2020 . (C) Rounding (i) Monthly specified child allowance Any increase under subparagraph (A) which is not a multiple of $10 shall be rounded to the nearest multiple of $10. (ii) Initial threshold amount Any increase under subparagraph (B) which is not a multiple of $5,000 shall be rounded to the nearest multiple of $5,000. (c) Specified child For purposes of this section— (1) In general The term specified child means, with respect to any taxpayer for any calendar month, an individual—