Chevron deference has become increasingly controversial. Some Justices on the Supreme Court have stated that they would overrule Chevron, and others have urged that it be curtailed. If Chevron were merely modified rather than overturned, it is unclear what that modified Chevron would look like. This Article argues that the time has come to narrow Chevron’s domain by limiting Chevron deference to interpretations announced in rulemaking and not those announced in adjudication. Under the classic formulation of Chevron, a court should defer to an agency’s reasonable interpretation of ambiguous statutory language. This formulation is grounded in the notion that Congress, at least implicitly, signals a preference for agency rather than judicial d...