To ensure the availability of spectrum to amateur radio operators.

Amateur Radio Spectrum Protection Act of 2003 - Prohibits the Federal Communications Commission (FCC), after July 1, 2003, from reallocating primary allocations of bands of frequencies of the amateur radio and amateur satellite services, diminishing the secondary allocations of such bands to such services, or making additional allocations within such bands that would substantially reduce their utility to the amateur radio or satellite service, unless the FCC provides equivalent replacement spectrum to amateur radio and satellite service.