There were nearly 20,000 airports1 in the United States , with about 5,300 of these open to the public and known as public-use airports, as of January 2004. The Federal Aviation Administration includes about 3,400 existing public-use airports in its National Plan of Integrated Airport Systems (NPIAS). The NPIAS includes both commercial and general aviation airports that are eligible to receive grants under the Airport Improvement Program. Commercial service airports are defined as public airports receiving scheduled passenger service with at least 2,500 enplaned passengers per year. These airports handle the vast majority of enplanements in the United States . In 2004, there were 513 commercial service airports.
U.S. Department of Transportation, Federal Aviation Administration, National Planning Division, personal communication, Feb. 22, 2005.
1 Includes civil and joint-use civil-military airports, heliports, STOL (short take off and landing) ports, and seaplane bases in the United States and its territories.