Reagan National Airport is subject to a federally mandated perimeter limitation and cannot accommodate flights to cities outside a 1,250 mile radius, with limited exceptions. The U.S. Department of Transportation has issued 24 "beyond-perimeter slot exemptions" which allow specified carriers to operate 12 daily round-trip flights to cities outside the perimeter. These exemptions are allocated as follows:

* US Airways (8 slots operating as 3x Phoenix, 1x Las Vegas)
* Alaska Airlines (6 slots operating as 2x Seattle/Tacoma, 1x Los Angeles)
* Frontier Airlines (6 slots operating as 3x Denver)
* Delta Air Lines (2 slots operating as 1x Salt Lake City)
* United Airlines (2 slots operating as 1x Denver)

In 1999, Senator John McCain of Arizona introduced legislation to remove the 1250-mile perimeter restriction, infuriating local residents concerned about noise and traffic from increased service by larger, long-haul aircraft. McCain argued that the move would improve competition, while critics charged he was supporting the interests of Phoenix, Arizona-based America West Airlines (AWA). In the end the restriction was not lifted, but the FAA was permitted to add additional exemptions, which went not to AWA but to competitor Alaska Airlines. America West (now US Airways) would later gain additional exemptions for non-stop service to Phoenix in 2004.