FAA Airport Improvement Program (AIP) Grants

The FAA Airport Improvement Program (AIP) is the primary federal mechanism through which the United States funds capital development at public-use airports. Authorized under Title 49 of the United States Code and administered by the Federal Aviation Administration, AIP distributes federal grants to airport sponsors for eligible infrastructure projects. Understanding AIP is essential for airport operators, state aviation agencies, and local governments navigating the federal funding landscape for aviation infrastructure.

Definition and scope

AIP was created by the Airport and Airway Improvement Act of 1982 and is periodically reauthorized through FAA reauthorization legislation. Funding flows from the Airport and Airway Trust Fund, which is capitalized by aviation-related excise taxes including taxes on passenger tickets, cargo waybills, and aviation fuel (FAA Budget and Funding).

The program covers airports included on the National Plan of Integrated Airport Systems (NPIAS), which the FAA updates every two years. The NPIAS identifies airports considered significant to national air transportation — as of the 2023–2027 edition, the FAA identified approximately 3,300 airports in the NPIAS (FAA NPIAS 2023–2027). Eligible airport sponsors include public agencies such as municipalities, counties, states, and certain private entities that own public-use airports meeting NPIAS criteria.

Eligible project categories under AIP include:

  1. Runway and taxiway construction, reconstruction, and rehabilitation
  2. Airport safety improvements including runway safety areas and obstacle removal
  3. Airport security infrastructure
  4. Noise compatibility planning and mitigation measures consistent with FAA Noise Abatement Programs
  5. Land acquisition for aeronautical purposes
  6. Terminal development (subject to strict caps tied to enplanement levels)
  7. Airport master planning and environmental studies

AIP does not fund revenue-generating concession facilities, automobile parking structures, or projects primarily serving non-aeronautical purposes.

How it works

AIP grants operate on a cost-sharing model. The federal share for most projects at primary commercial service airports is 75 percent of allowable project costs. For airports in states with high federal land percentages, the federal share can reach 90 percent. Smaller general aviation airports typically receive an 90 to 95 percent federal share, reflecting the limited local revenue base of those sponsors (49 U.S.C. § 47109).

The annual AIP apportionment process allocates funds to airport sponsors through two channels:

Entitlement funds (also called apportioned funds) are distributed by formula based on factors including passenger enplanements, cargo tonnage, and airport type. A primary airport serving more than 10,000 annual enplanements receives a minimum annual entitlement. These funds are predictable and allow sponsors to plan multi-year capital programs.

Discretionary funds are awarded competitively by FAA regional and headquarters offices based on project merit, safety priority, and national program objectives. Discretionary grants address projects that exceed a sponsor's entitlement level or fall into high-priority categories such as runway safety area improvements.

To receive a grant, a sponsor submits a project application through FAA's Airport Data and Information Portal (ADIP). The FAA reviews eligibility, environmental compliance under the National Environmental Policy Act (NEPA), and conformance with the sponsor's FAA-approved Airport Layout Plan (ALP). Grant agreements include assurances — legally binding commitments the sponsor makes to the federal government covering nondiscrimination, airport access, and maintenance of the funded asset for its useful life, typically 20 years for pavement projects.

FAA Airport Certification Standards intersect with AIP because certificated airports must maintain standards aligned with those assurances throughout the grant period.

Common scenarios

Runway rehabilitation at a commercial service airport: A medium-hub airport with deteriorating pavement requests an AIP grant to mill and overlay a primary runway. Because the airport is a primary commercial service airport, the federal share is 75 percent. The sponsor uses accumulated entitlement funds and supplements with discretionary funding. The project must comply with FAA Advisory Circular 150/5370-10 construction standards and requires an updated ALP prior to grant execution.

General aviation airport safety area upgrade: A small municipal airport with fewer than 10,000 annual enplanements needs to bring its runway safety area (RSA) into compliance with FAA design standards. As a general aviation airport, it qualifies for a 90 percent federal share. The FAA may flag such projects for priority discretionary funding because RSA deficiencies directly affect FAA safety regulations compliance.

Noise land acquisition: An airport sponsor adjacent to a densely populated neighborhood uses AIP funds for residential land acquisition under an FAA-approved Part 150 noise compatibility program. The program authorizes use of AIP for noise mitigation, though total noise set-aside funding is subject to annual statutory caps.

Decision boundaries

Several threshold conditions determine whether a project is AIP-eligible and what funding level applies:

NPIAS inclusion is a threshold requirement. An airport not listed in the NPIAS cannot receive AIP funds regardless of project type or local need.

Airport category affects entitlement and federal share. Primary airports — those with more than 10,000 annual commercial enplanements — receive larger annual entitlements but a lower federal share (75 percent) compared to non-primary airports. Non-primary airports receive a higher federal share (up to 95 percent) but smaller entitlement amounts, with a statutory cap of $150,000 per year in entitlement funds for the smallest eligible airports (49 U.S.C. § 47114).

Terminal development caps restrict AIP use for terminal buildings. AIP can fund terminal development only at non-primary airports and only up to $200 per enplaned passenger annually, as set by statute.

Environmental clearance must precede grant execution. Projects lacking NEPA documentation — whether a Categorical Exclusion, Environmental Assessment, or Environmental Impact Statement — cannot advance to grant agreement regardless of other eligibility.

Understanding how AIP fits within the broader structure of federal aviation oversight is aided by reviewing the FAA's scope and authority as the administering agency for all civil aviation programs, including the grant assurances that bind airport sponsors for the life of funded infrastructure.