Chevron v. Natural Resources Defense Council

The Court held that courts must defer to reasonable agency interpretations of ambiguous statutes the agencies administer.

Overview

The EPA defined stationary sources under the Clean Air Act with a plantwide bubble concept that eased compliance. Justice Stevens, for a Court with no dissenting votes, articulated the two-step framework: first ask whether Congress directly spoke to the precise question; if the statute is silent or ambiguous, defer to the agency's permissible construction. Chevron deference became the most cited doctrine in administrative law, empowering the modern administrative state and generating decades of debate. It was overruled in Loper Bright in 2024, which restored independent judicial judgment on statutory meaning and closed the Chevron era.