The question of how best to design a new agency is of immense public importance. Congress creates new agencies and reforms agency structures with some regularity, while commentators frequently call for the creation of new or redesigned agencies. Scholars have, as a result, increasingly turned to studying the diversity of agency structures and questions of agency design. In this Essay, we tackle one of the decisions that must be made in designing any new agency—the choice between a single-director agency and a multimember commission—and we make a general case against multimember commissions. For the most part, scholarly discussion of these structures is interwoven with questions of agency independence. But these two questions—singularity and independence—can be pulled apart and assessed separately. Yet surprisingly little of the existing literature focuses systematically on this decision. The central benefits of single-director agencies are that they better ensure agency efficacy at accomplishing statutory mandates, and that they offer clearer lines of responsibility and thus accountability for agency failures. Proponents of multimember commissions concede the inefficiency of its design but hold that inefficiency is desirable because it serves as a defense against liberty-infringing actions. We term this the “safeguards of liberty fallacy†and show that it rests on faulty foundations. The most often discussed benefits of multimember commissions are that they enhance deliberation and accountability. Dissents also serve as a “fire alarm†signal to Congress and the courts of potential agency malfeasance and thus enable greater accountability. We do not disagree that these are potential benefits of a multimember commission, but we believe that these benefits are wildly overvalued, and their costs are widely undervalued. In addition to suffering from baseline problems, these arguments fail to take seriously the reality of asymmetric political polarization. Finally, we turn to the relationship between multimember commissions and regulated entities. We argue that the adjudicatory origins of multimember commissions cannot carry the weight of that design choice in an era of rulemaking, and we also suggest that multimember commissions might suffer from more acute industry capture than single-director agencies. In short, the general case against multimember commissions is extremely strong. Scholars and policymakers would be well-advised to recommend singledirector agencies as a default presumption. [ABSTRACT FROM AUTHOR]