An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

General Conformity

Basic Information About the General Conformity Rule

LaGuardia Airport in New York City, NYGeneral Conformity covers most aspects of airport activities funded by federal agencies. The Federal Aviation Administration (FAA) and EPA have coordinated to produce guidelines for General Conformity at airports.

What the Rule Does

The purpose of the General Conformity rule is to ensure that :

  • federal activities do not cause or contribute to new violations of National Ambient Air Quality Standards (NAAQS);
  • actions do not worsen existing violations of the NAAQS; and
  • attainment of the NAAQS is not delayed.

General Conformity covers most aspects of federally funded or approved actions not covered by the Transportation Conformity program.

In November 1993, EPA promulgated two sets of regulations to implement Section 176(c) of the Clean Air Act. First, on November 24, EPA promulgated the Transportation Conformity regulations, which apply to highways and mass transit. These regulations establish the criteria and procedures for determining whether transportation plans, programs, and projects funded under title 23 U.S. C. or the Federal Transit Act conform with the State Implementation Plan (SIP) (58 FR 62188). Then, on November 30, EPA promulgated a second set of regulations, known as the General Conformity regulations, which apply to all other federal actions. These regulations ensured that other federal actions also conformed to the SIPs (58 FR 63214).

Learn more about the promulgated Transportation Conformity and the General Conformity regulations, and the final revisions to the General Conformity rule.


EPA has developed several guidance documents on General Conformity.

Learn more and read the guidance documents on the General Conformity Regulations

Learn more about the General Conformity Training Modules