Research on public management reform has taken a decidedly disciplinary turn. Since the late 1990s, analytical issues are less often framed in terms of the New Public Management. As part of the disciplinary turn, much recent research on public management reform is highly influenced by the three new institutionalisms. However, these studies have implicitly been challenged by a competing research program on public management reform that is emphatically processual in its theoretical foundations. This article develops the challenge in a more explicit fashion. It provides a theoretical restatement of the competing "institutional processualist" research program and compares its substantive findings with those drawn from the neoinstitutionalisms. The implications of this debate about public management reform for comparative historical analysis and neoinstitutional theories are discussed. © 2006 Blackwell Publishing.