Chevron U.S.A. Inc. v. Natural Resources Defense Council, Inc. (1984) Definition

A landmark U.S. Supreme Court decision that set the boundaries of federal administrative agency authority to regulate under federal statutes. Chevron established a two-tiered level of review, depending on Congress' legislative intent as expressed (or not expressed) in a statute.

When Congress' intent on a particular issue is clearly expressed in a statute, a reviewing court must give effect to that intent. (Chevron U.S.A. Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837, 842-43 (1984).) But when Congress hasn't spoken to an issue, courts must ask how Congress delegated authority to the agency to fill in the blanks.

If Congress expressly delegated that authority, the agency's regulatory interpretation is controlling unless a court finds it to be "arbitrary, capricious, or manifestly contrary to the statute." By contrast, when Congress' delegation of authority to an agency was implicit, courts must defer to reasonable agency interpretations of the statute. Courts aren't free simply to substitute their own statutory interpretation for that of the agency. Chevron, 467 U.S. at 844.

The Supreme Court overruled Chevron in Loper Bright Enterprises v. Raimondo, 603 U.S. ___ (2024).

Here's the full text of the decision: Chevron U.S.A. Inc. v. Natural Resources Defense Council, Inc.