Abstract: Chevron, U.S.A., Inc. v. National Resources Defense Council, Inc., the foundation for much of contemporary administrative law, is under siege. Several members of the Supreme Court have suggested that they would like to overrule it. Under standard principles of stare decisis, doing that would be a serious mistake. Even if Chevron was wrongly decided, overruling it would create an upheaval—a large shock to the legal system, producing a great deal of confusion, more conflicts in the courts of appeals, and far greater politicization of administrative law. For example: What would happen to the countless regulations that have been upheld under the Chevron framework? Would they be newly vulnerable? More fundamentally,, a predictable effect of overruling Chevron would be to ensure a far greater role for judicial policy preferences in statutory interpretation and far more common splits along ideological lines. There is also the question of reliance interests: For decades, Congress has legislated against the background set by Chevron, and the resulting statutes reflect an understanding that the Court’s framework will apply. Though the argument for overruling Chevron is unconvincing, its critics have legitimate concerns. Those concerns should be addressed by (1) insisting on a fully independent judicial role in deciding whether a statute is ambiguous at Step One; (2) invalidating arbitrary or unreasonable agency interpretations at Step Two; and (3) deploying canons of construction, including those that are designed to serve nondelegation functions and thus to cabin executive authority.