cost-sharing reductions under section 1402 of the Patient Protection and Affordable Care Act for calendar year 2018 exceeds an amount equal to 0.504 percent of the gross domestic product for such calendar year. . (b) Effective date (1) In general Except as otherwise provided in this subsection, the amendments made by this section shall apply to taxable years beginning after December 31, 2017. (2) Advance payment not applicable to off-Exchange coverage The amendment made by subsection (a)(4)(A) shall take effect on January 1, 2018. (3) Reporting The amendment made by subsection (a)(4)(B) shall apply to coverage provided for months beginning after December 31, 2017. (4) Modification of applicable percentage The amendment made by subsection (b) shall apply to taxable years beginning after December 31, 2018. 203. Premium tax credit (a) Repeal of premium tax credit Section 36B of the Internal Revenue Code of 1986 is amended by adding at the end the following new subsection: (h) Termination No credit shall be allowed under this section with respect to any coverage month which begins after December 31, 2019. . (b) Repeal of advance payment of, and eligibility determination for, premium tax credit Section 1412 of the Patient Protection and Affordable Care Act, as amended by the preceding provisions of this subtitle, is amended by adding at the end the following new subsection: (g) Termination with respect to premium tax credit Effective January 1, 2020, no provision of this section or section 1411 shall apply to the credit allowed under section 36B of the Internal Revenue Code of 1986 (or to the advance payment of, or determination of eligibility for, such credit or payment). . (c) Effective dates (1) Premium tax credit The amendment made by subsection (a) shall apply to months beginning after December 31, 2019, in taxable years ending after such date. (2) Eligibility determinations The amendment made by subsection (b) shall take effect on January 1, 2020. 204. Small business tax credit (a) In general Section 45R of the