1. Short title This Act may be cited as the Young Adult Tax Credit Act . 2. Establishment of refundable young adult tax credit with monthly advance payment (a) In general Subpart A of part IV of subchapter A of chapter 1 of the Internal Revenue Code of 1986 is amended by inserting after section 24 the following new sections: 24A. Monthly young adult tax credit (a) Allowance of credit There shall be allowed as a credit against the tax imposed by this chapter for the taxable year the sum of the monthly specified young adult allowances determined with respect to the taxpayer under subsection (b) for each calendar month during such taxable year. (b) Monthly specified young adult allowance (1) In general For purposes of this section, the term monthly specified young adult allowance means the sum of $500 for each taxpayer or dependent of the taxpayer who is a specified young adult for any calendar month. (2) Monthly specified young adult allowance In the case of any month beginning after December 31, 2024, the $500 amount in paragraph (1) shall 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 2024. (c) Specified young adult The term specified young adult means an individual— (1) who, as of the close of such month, is at least 18 and will not have attained age 25, and (2) who either is a citizen, national, or resident of the United States. (d) Denial of credit to dependents No credit shall be allowed under this section to any individual with respect to whom a deduction under section 151 is allowable to another taxpayer for a taxable year beginning in the calendar year in which such individual's taxable year begins. (e) Credit refundable If the taxpayer (in the case of a joint return, either spouse) has a principal place of abode (determined as provided in section 32) in the United