Abstract: Chevron, U.S.A. v. Natural Resources Defense Council lays out a two-step process that courts must follow when they review a federal agency's construction of a federal statute. We argue that Chevron, rightly understood, has only one step. The single question is whether the agency's construction is permissible as a matter of statutory interpretation. The two Chevron steps both ask this question, just in different ways, and are thus mutually convertible: any opinion written in terms of one step can be written, without loss of content, in terms of the other step. Chevron's artificial division of a unitary inquiry causes material confusion among commentators and courts, and has no benefits; administrative law should jettison the two-step framework.