Many authors discuss judicial oversight of agency actions. Our subject, which is less well examined, is agencies’ role in modulating that oversight. We consider cases in which the timing or form of an agency action has curtailed judicial review of the agency’s policy choices. In some such cases, the agency’s choice of form deprived the court of statutory or Article III jurisdiction. In others, the court chose to delay or deny review to avoid interfering with agency policy development. Despite these differences, though, all such “reviewability” cases pose important constitutional questions about the degree to which an agency should be able to limit judicial oversight of its activities. We argue that courts pay too little attention to these questions, and we propose a more systematic framework for evaluating the constitutional implications of allowing an agency to modulate the availability of judicial review by manipulating the structure of its actions.