; and (2) remain available until expended and not be transferable. 7. Return of excess tax receipts to States (a) In general Section 9503(c) of the Internal Revenue Code of 1986 is amended by adding at the end the following: (6) Return of excess tax receipts to States for surface transportation purposes (A) In general On the first day of each of fiscal years 2019, 2020, 2021, and 2022, the Secretary, in consultation with the Secretary of Transportation, shall— (i) determine the excess (if any) of— (I) the amounts appropriated in such fiscal year to the Highway Trust Fund under subsection (b) which are attributable to the taxes described in paragraphs (1) and (2) thereof (after the application of paragraph (4) thereof) over the sum of— (II) the amounts so appropriated which are equivalent to— (aa) such amounts attributable to the core programs financing rate for such year, plus (bb) the taxes described in paragraphs (3)(C), (4)(B), and (5) of subsection (c), and (ii) allocate the amount determined under clause (i) among the States (as defined in section 101(a) of title 23, United States Code) for surface transportation (including mass transit and rail) purposes so that— (I) the percentage of that amount allocated to each State, is equal to (II) the percentage of the amount determined under clause (i)(I) paid into the Highway Trust Fund in the latest fiscal year for which such data are available which is attributable to highway users in the State. (B) Enforcement If the Secretary determines that a State has used amounts under subparagraph (A) for a purpose which is not a surface transportation purpose as described in subparagraph (A), the improperly used amounts shall be deducted from any amount the State would otherwise receive from the Highway Trust Fund for the fiscal year which begins after the date of the determination. . (b) Effective date The amendment made by this section shall take effect on October 1, 2018. 8. Reduction in taxes on gasoline, diesel fuel, kerosene, and special fuels funding Highway Trust