Chevron v. NRDC (1984)

The Clean Air Act Amendments of 1977 required permits for new or modified stationary sources of pollution in areas failing air quality standards. In 1981 the Reagan administration's Environmental Protection Agency adopted the bubble concept, treating an entire plant as a single source, so a company could modify equipment without a permit if total emissions did not rise. The Natural Resources Defense Council challenged the rule, and the D.C. Circuit struck it down. Chevron, which supported the rule, appealed along with the EPA.

On June 25, 1984, the Supreme Court unanimously upheld the rule, 6 to 0, with three justices not participating, in an opinion by Justice John Paul Stevens. The Court set out a two-step test: first, if Congress has directly spoken to the precise question, courts and agencies must follow its clear intent, and second, if the statute is silent or ambiguous, courts should defer to the agency's interpretation if it is reasonable. The Court reasoned that agencies have expertise and political accountability through the President that judges lack.

Chevron became the most cited case in administrative law, applied in thousands of lower court decisions, and both Democratic and Republican administrations relied on it to change policy. Over time, critics argued that it let agencies, rather than courts, say what the law is and encouraged shifting interpretations, while defenders said it respected agency expertise and accountability. In Loper Bright Enterprises v. Raimondo, decided June 28, 2024, the Court overruled Chevron, holding that the Administrative Procedure Act requires courts to exercise independent judgment, while leaving prior decisions that relied on Chevron in place.