There is allowed as a deduction for the taxable year an amount equal to the sum of the amounts contributed by the taxpayer during the taxable year to or under a trust or trusts described in section 501(c)(21).
The amounts described in subsection (b) shall be determined by using reasonable actuarial methods and assumptions which are not inconsistent with regulations prescribed by the Secretary.
In determining the amounts described in subsection (b), only those black lung benefit claims the payment of which is expected to be made from the trust shall be taken into account.
For purposes of this section, a taxpayer shall be deemed to have made a payment of a contribution on the last day of a taxable year if the payment is on account of that taxable year and is made not later than the time prescribed by law for filing the return for that taxable year (including extensions thereof).
No deduction shall be allowed under subsection (a) with respect to any contribution to a trust described in section 501(c)(21) other than a contribution in cash or in items in which such trust may invest under subclause (II) of section 501(c)(21)(A)(ii).
No deduction shall be allowed under section 162(a) with respect to any liability taken into account in determining the deduction under subsection (a) of this section of the taxpayer (or a predecessor).
If the amount of the deduction determined under subsection (a) for the taxable year (without regard to the limitation imposed by subsection (b)) with respect to a trust exceeds the limitation imposed by subsection (b) for the taxable year, the excess shall be carried over to the succeeding taxable year and treated as contributed to the trust during that year.
For purposes of this section, the term “black lung benefit claim” means a claim for compensation for disability or death due to pneumoconiosis under part C of title IV of the Federal Mine Safety and Health Act of 1977 or under any State law providing for such compensation.