The only airports, or portions of airports, eligible for AIP funding are public use airportsincluded in the National Plan of Integrated Airport Systems (NPIAS). An airport is defined in the law as any area of land or water used or intended for landing or takeoff of aircraft including appurtenant area used or intended for airport buildings, facilities, as well as rights of way together with the buildings and facilities. Special types of facilities such as seaplane bases and heliports are included in the airport categories listed below.

Thelaw categorizes airports by type of activities, including commercial service, primary, cargo service, reliever, and general aviation airports, as shown below:

Categories of Airport Activities
Airport Classifications Hub Type: Percentage of Annual Passenger Boardings Common Name
Commercial Service:
Publicly owned airports
that have at least 2,500
passenger boardings
each calendar year and
receive scheduled
passenger service
Have more than 10,000
passenger boardings
each year
1% or more
Large Hub
At least 0.25%,
but less than 1%
Medium Hub
At least 0.05%,
but less than 0.25%
Small Hub
More than 10,000,
but less than 0.05%
Nonhub Primary
Nonprimary Nonhub:
At least 2,500
and no more than than 10,000
Nonprimary Commercial Service
(Except Commercial Service)
Not Applicable


General Aviation (47102(8))

See Definitions of Airport Categories below for more information.

Definition of Airport Categories

  1. Commercial Service Airports are publicly owned airports that have at least 2,500 passenger boardings each calendar year and receive scheduled passenger service. Passenger boardings refer to revenue passenger boardings on an aircraft in service in air commerce whether or not in scheduled service. The definition also includes passengers who continue on an aircraft in international flight that stops at an airport in any of the 50 States for a non-traffic purpose, such as refueling or aircraft maintenance rather than passenger activity. Passenger boardings at airports that receive scheduled passenger service are also referred to as Enplanements.
    1. Nonprimary Commercial Service Airports are Commercial Service Airports that have at least 2,500 and no more than 10,000 passenger boardings each year.
    2. Primary Airports are Commercial Service Airports that have more than 10,000 passenger boardings each year. Hub categories for Primary Airports are defined as a percentage of total passenger boardings within the United States in the most current calendar year ending before the start of the current fiscal year. For example, calendar year 2014 data are used for fiscal year 2016 since the fiscal year began 9 months after the end of that calendar year. The table above depicts the formulae used for the definition of airport categories based on statutory provisions cited within the table, including Hub Type described in 49 USC 47102.
  2. Cargo Service Airports are airports that, in addition to any other air transportation services that may be available, are served by aircraft providing air transportation of only cargo with a total annual landed weight of more than 100 million pounds. "Landed weight" means the weight of aircraft transporting only cargo in intrastate, interstate, and foreign air transportation. An airport may be both a commercial service and a cargo service airport.
  3. Reliever Airports are airports designated by the FAA to relieve congestion at Commercial Service Airports and to provide improved general aviation access to the overall community. These may be publicly or privately-owned.
  4. General Aviation Airports are public-use airports that do not have scheduled service or have less than 2,500 annual passenger boardings (49 USC 47102(8)). Approximately 88 percent of airports included in the NPIAS are general aviation.

In cooperation with the aviation community, FAA completed two top down reviews of the existing network of general aviation facilities included in the NPIAS. The results of these efforts are contained in two reports (General Aviation Airports: A Nation Asset), which capture the diverse functions and economic contributions GA airport make to their communities and the Nation. Five new categories for airports serving general aviation (includes nonprimary commercial service, relievers and general aviation) were developed based on existing activity levels. These roles are shown below.

General Aviation Airport Categories
Role Description
National Supports the national and state system by providing communities with access to national and international markets in multiple states and throughout the United States.
Regional Supports regional economies by connecting communities to statewide and interstate markets.
Local Supplements communities by providing access to primarily intrastate and some interstate markets.
Basic Links the community with the national airport system and supports general aviation activities (e.g., emergency services, charter or critical passenger service, cargo operations, flight training and personal flying).
Unclassified Provides access to the aviation system.

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