The Supreme Court says that Chevron has two steps: Is the statute ambiguous (Step One), and, if so, is the agency\u27s interpretation of the ambiguous provision a permissible one (Step Two)? Yet over the last three decades, the DC Circuit has inserted an intermediate step between Steps One and Two: Did the agency recognize that the statutory provision is ambiguous? If not, then the DC Circuit refuses to proceed to Chevron Step Two and remands the matter to the agency. This doctrine- which we dub Chevron Step One-and-a-Half -has led to dozens of agency losses in the DC Circuit and DC federal district court, but it has gone entirely unmentioned in administrative law casebooks and is rarely referenced in the academic literature. The few who h...