Maritime Goods Movement Act for the 21st Century

Maritime Goods Movement Act for the 21st Century - Directs the U.S. Customs and Border Protection (CBP) to impose a Maritime Goods Movement User Fee of 0.125% on all commercial cargo (except a U.S. export) that: (1) is unloaded from or loaded on a commercial vessel at a U.S. port, or (2) enters a U.S. point of entry.

Prescribes a special rule prohibiting the imposition of such fee on: (1) cargo (except crude oil with respect to Alaska) loaded on a vessel in a mainland U.S. port and transported for use or consumption in Alaska, Hawaii, or any U.S. possession; (2) cargo loaded on a vessel in Alaska, Hawaii, or any U.S. possession and transported for use or consumption in the U.S. mainland, Alaska, Hawaii, or U.S. possession; (3) the unloading of such cargo in Alaska, Hawaii, or U.S. possession, or U.S. mainland, respectively; or (4) cargo loaded on a vessel in Alaska, Hawaii, or U.S. possession and unloaded in the state or U.S. possession in which loaded, or passengers transported on U.S.-flag vessels operating solely within Alaskan or Hawaiian waters and adjacent international waters.

Prohibits imposition of such fee on: (1) on the United States or any U.S. agency, or (2) a nonprofit organization or cooperative for cargo intended for use in humanitarian or development assistance overseas.

Requires use of up to $10 million of fees collected during any fiscal year for administrative expenses of the Department of Homeland Security (DHS), the Army Corps of Engineers, and the Department of Transportation (DOT).

Makes certain fee allocations for: (1) harbor maintenance programs; (2) low-use ports; and (3) super donor ports to carry out projects or activities under a competitive grant for maritime improvement projects for movement of goods, as well as for other specified maritime improvement projects for movement of international maritime cargo.

Defines "super donor port" as a port for which average expenditures in the 5 previous fiscal years: (1) from the Harbor Maintenance Trust Fund, for fiscal years beginning before enactment of this Act, are less than 10% percent of the total average amount of harbor maintenance taxes collected through landings at the port in such fiscal years; or (2) from the amounts collected for the Maritime Goods Movement User Fee, for fiscal years starting after enactment of this Act, are less than 10% of the total average amount of such fees collected through landings at the port.

Establishes a Competitive Grant Program for Goods Movement.

Amends the Internal Revenue Code to repeal the harbor maintenance tax.

Declares that nothing in this Act shall be construed to prevent application of requirements that locally prevailing wages (Davis-Bacon Act) be paid to various classes of laborers and mechanics working on harbor maintenance improvement projects.