The allocation of cadaveric organs for transplantation in the United States is governed by a process of private regulation. Through the Organ Procurement and Transplantation Network (OPTN), stakeholders and public representatives determine the substantive content of allocation rules. Between 1994 and 2000 the U.S. Department of Health and Human Services conducted a rule making to define more clearly the public and private roles in the determination of organ allocation policy. Several prominent liver transplant centers that were losing market share as a result of the proliferation of transplant centers used the rule making as a vehicle for challenging the local priority for organ allocation inherent in the OPTN rules. The process leading to the final rule provides a window on the politics of organ allocation. It also facilitates an assessment of the strengths and weaknesses of private rule making. Overall, private rule making appears to be relatively effective in tapping the technical expertise and tacit knowledge of stakeholders to allow for the adaptation of rules in the face of changing technology and information. However, the particular system of representation employed may give less influence to some stakeholders than they would have in public regulatory arenas, giving them an incentive to seek public rule making as a remedy for their persistent losses within the framework of private rule making.