533 U.S. 218 (2001) (Supreme Court of the United States)
United States v. Mead Corp.
Do Customs classification ruling letters—informal, non–notice-and-comment determinations binding only on the addressee—qualify for Chevron deference, or are they instead entitled at most to Skidmore respect based on their persuasive force?
Chevron deference applies when (1) Congress has delegated authority to the agency generally to make rules carrying the force of law, and (2) the agency interpretation claiming deference was promulgated in the exercise of that authority. Where these conditions are not met, an agency's interpretation may be entitled only to Skidmore deference—the weight accorded to an interpretation proportional to its power to persuade, considering factors such as the thoroughness of the agency's consideration, the validity of its reasoning, consistency over time, and the agency's expertise and care.
Customs classification ruling letters do not warrant Chevron deference because they are not issued through procedures indicating congressional intent that they carry the force of law. Such rulings may, however, merit Skidmore deference to the extent they are persuasive. The judgment was vacated and remanded for the lower court to evaluate the ruling under Skidmore.
Mead is foundational for the threshold inquiry—Chevron step zero—that governs whether Chevron's deferential framework applies at all. It clarifies that formal process and other indications that Congress meant the agency to act with the force of law are key triggers for Chevron. In their absence, courts default to Skidmore's persuasive standard. For students and practitioners, Mead reframes deference analysis as a two-stage inquiry: (1) eligibility for Chevron based on congressional delegation and procedural posture, and (2) if ineligible, application of Skidmore. The decision has broad implications across administrative practice because many agency interpretations arise in informal formats (letters, manuals, FAQs, guidance). Mead ensures these receive measured respect without automatic Chevron deference, promoting accountability and procedural regularity while preserving space for agencies' expertise to influence courts when their reasoning is careful, consistent, and persuasive.