of a correct social security number required under subsection (h)(1) of section 36B (subsection (g)(1) of section 36B in the case of months beginning before January 1, 2020) to be included on a return. . (d) Effective dates (1) Application to current health insurance premium tax credit (A) In general Except as otherwise provided in this paragraph, the amendment made by subsection (a) shall apply to taxable years ending after the date of the enactment of this Act. (B) Advance payment Section 36B(g)(2) of the Internal Revenue Code of 1986, as amended by this section and as in effect for months beginning before January 1, 2020, shall apply to months beginning after the date of the enactment of this Act. (2) Application to new health insurance premium tax credit The amendment made by subsection (b) shall apply to months beginning after December 31, 2019, in taxable years ending after such date. (3) Treatment as mathematical or clerical error The amendments made by subsection (c) shall apply to taxable years ending after the date of the enactment of this Act.