26 U.S.C. § 45G: Railroad track maintenance credit

For purposes of section 38, the railroad track maintenance credit determined under this section for the taxable year is an amount equal to 40 percent (50 percent in the case of any taxable year beginning before January 1, 2023 ) of the qualified railroad track maintenance expenditures paid or incurred by an eligible taxpayer during the taxable year. $3,500, multiplied by the number of miles of railroad track owned or leased by the eligible taxpayer as of the close of the taxable year, and the number of miles of railroad track assigned for purposes of this subsection to the eligible taxpayer by a Class II or Class III railroad which owns or leases such railroad track as of the close of the taxable year. such assignment may be made only once per taxable year of the Class II or Class III railroad and shall be treated as made as of the close of such taxable year, such mile may not be taken into account under this section by such railroad for such taxable year, and such assignment shall be taken into account for the taxable year of the assignee which includes the date that such assignment is treated as effective. any Class II or Class III railroad, and any person who transports property using the rail facilities of a Class II or Class III railroad or who furnishes railroad-related property or services to a Class II or Class III railroad, but only with respect to miles of railroad track assigned to such person by such Class II or Class III railroad for purposes of subsection (b). For purposes of this section, the term “qualified railroad track maintenance expenditures” means gross expenditures (whether or not otherwise chargeable to capital account) for maintaining railroad track (including roadbed, bridges, and related track structures) owned or leased as of January 1, 2015 , by a Class II or Class III railroad (determined without regard to any consideration for such expenditures given by the Class II or Class III railroad which made the assignment of such track). For purposes of this section, the terms “Class II railroad” and “Class III railroad” have the respective meanings given such terms by the Surface Transportation Board. Rules similar to the rules of paragraph (1) of section 41(f) shall apply for purposes of this section. For purposes of this subtitle, if a credit is allowed under this section with respect to any railroad track, the basis of such track shall be reduced by the amount of the credit so allowed. The amendment made by this section [amending this section] shall apply to expenditures paid or incurred in taxable years beginning after December 31, 2016 . Assignments, including related expenditures paid or incurred, under paragraph (2) of section 45G(b) of the Internal Revenue Code of 1986 for taxable years ending after January 1, 2017 , and before January 1, 2018 , shall be treated as effective as of the close of such taxable year if made pursuant to a written agreement entered into no later than 90 days following the date of the enactment of this Act [ Feb. 9, 2018 ].” The amendment made by subsection (a) [amending this section] shall apply to expenditures paid or incurred in taxable years beginning after December 31, 2014 . The amendment made by subsection (b) [amending this section] shall apply to expenditures paid or incurred in taxable years beginning after December 31, 2015 .”