The Congressional Review Act permits Congress to veto proposed regulations via a joint resolution, and prohibits an agency from reissuing a rule “in substantially the same form” as the vetoed rule. Some scholars—and officials within the agencies themselves—have understood the “substantially the same” standard to bar an agency from regulating in the same substantive area covered by a vetoed rule. Courts have not yet provided an authoritative interpretation of the standard. This Article examines a spectrum of possible understandings of the standard, and relates them to the legislative history (of both the Congressional Review Act itself and the congressional veto of the Occupational Safety and Health Administration’s ergonomics rule), the sta...