The practice of awarding good time credits in United States prisons was developed early in the nineteenth century both to further public policy and to enhance prison management. Good time was seen as a method for alleviating prison crowding, controlling prison behavior, and rewarding rehabilitation efforts. Though parole policies eventually overshadowed good time as an early release tool, corrections administrators in virtually every state retained some form of credit-based release. Currently, overcrowded prisons, constraints over population control mechanisms, and the increased need to ensure effective prison management have combined to make good time an issue of growing importance in the criminal justice system. In this article the present state of good time policy and research is examined, and an agenda for systematic review of good time policies and practices is outlined. While the use of good time in U.S. prisons is found to be growing, policymakers and prison administrators continue to rely upon untested assumptions when defending good time practices. We propose a research agenda that would examine (a) how good time is understood by prison personnel, (b) the actual operation of good time systems, (c) the utility of good time as a prison management device, (d) its role in rehabilitation, and (e) the special risks that good time releases pose to the community.