threshold amount means— (i) $400,000, in the case of a joint return or surviving spouse (as defined in section 2(a)), (ii) $300,000, in the case of a head of household (as defined in section 2(b)), and (iii) $200,000, in any other case. (4) Other terms For purposes of this subsection— (A) 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 clause (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). (B) 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. . (c) Inflation adjustments Subsection (i) of section 24 of the Internal Revenue Code of 1986 is amended to read as follows: (i) Adjustments for inflation In the case of any taxable year beginning after December 31, 2024— (1) In general The dollar amounts in subsection (a) and clauses (i) and (iii) of subsection (b)(3)(A) shall each be increased by an amount equal to— (A) such dollar amount, multiplied by (B) 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 2023. (2) Rounding Any increase under the preceding sentence— (A) which is not a multiple of $10, in the case of the amount in subsection (a), shall be rounded to the nearest multiple of $10, and (B) which is not a multiple of $5,000, in the case of the amounts in subsection (b)(3)(A), shall be rounded to the nearest multiple of $5,000. . (d) Qualifying child rules (1) In general Subsection (c) of section 24 of the Internal Revenue Code of 1986 is amended to read as follows: (c) Qualifying month