; or (B) who is eligible for a payment under a plan described in subsection (b) with respect to such taxable year. (2) Restriction on refundable credit In the case of any person to whom a credit would be allowed against taxes imposed by a possession which does not have a mirror code tax system if the provisions of such section 24 had been in effect in such possession for the taxable year (and who is not described in paragraph (1)(B)), section 24(h)(8) of such Code (as added by this Act) shall not apply to such person for such taxable year. (d) Definitions and special rules (1) Possession of the United States For purposes of this section, the term possession of the United States includes the Commonwealth of Puerto Rico and the Commonwealth of the Northern Mariana Islands. (2) Mirror code tax system For purposes of this section, the term mirror code tax system means, with respect to any possession of the United States, the income tax system of such possession if the income tax liability of the residents of such possession under such system is determined by reference to the income tax laws of the United States as if such possession were the United States. (3) Treatment of payments For purposes of section 1324(b)(2) of title 31, United States Code, the payments under this section shall be treated in the same manner as a refund due from the credit allowed under section 24 of the Internal Revenue Code of 1986. III Dependent Care Assistance 301. Refundability and enhancement of child and dependent care tax credit (a) In general Section 21 is amended by adding at the end the following new subsection: (g) Special rules for 2019 and 2020 In the case of any taxable year beginning in 2019 or 2020— (1) Credit made refundable In the case of an individual other than a nonresident alien, the credit allowed under subsection (a) shall be treated as a credit allowed under subpart C (and not allowed under this subpart). (2) Increase in applicable percentage Subsection (a)(2) shall be applied— (A) by substituting 50 percent for 35