Maritime Fuel Tax Parity Act

This bill amends the Internal Revenue Code to extend an existing excise tax exemption for alternative motorboat fuels sold as supplies for vessels or aircraft to also cover certain vessels that serve only one coast. Sec. 2, Exemption from excise tax on alternative motorboat fuels extended to include certain vessels serving only one coast: The bill adds a new sentence to Section 4041(g) of the Internal Revenue Code, specifying that the exemption from excise tax under subsection (a)(2) also applies to fuel sold for use or used by a vessel that is both described in Section 4042(c)(1) and actually engaged in trade between Atlantic or Pacific ports of the United States, including any territory or possession. This amendment applies to fuel sold for use or used after December 31, 2025.