Before June 2024, a type of judicial deference that was afforded to an administrative agency's interpretation of a statute that the agency was responsible for enforcing. The doctrine was articulated in Chevron, U.S.A., Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837 (1984). Under Chevron, a reviewing court generally deferred to an administrative agency's interpretation of a statute if:

For examples of how the courts applied Chevron deference, see Practice Note, Excepted Benefits and Legal Update, Federal Court Instructs EEOC to Reconsider Final ADA/GINA Wellness Regulations.

By contrast, administrative agency interpretations that were not the result of a formal adjudication or notice-and-comment rulemaking (for example, interpretations stated in opinion letters, technical releases, policy statements, agency manuals, and enforcement guidelines) did not receive Chevron deference (Christiansen v. Harris Cnty., 529 U.S. 576, 587 (2000)).

In June 2024, the Supreme Court (in a 6-3 decision) overruled its 1984 Chevron ruling (Loper Bright Enters. v. Raimondo, (June 28, 2024)). The Supreme Court concluded (among other reasons) that Chevron could not be reconciled with the Administrative Procedure Act (APA), which requires courts to apply their own judgment in deciding questions of law—even in cases involving administrative agencies. The Loper Bright ruling will generally make it more difficult for the federal administrative agencies to defend challenges to their regulations going forward.