Although proponents of the justice model have a variety of perspectives, the core values on which most agree are proportionality, equity, retrospectivity, and predictability. Numerous problems surround the implementation of the justice model in probation; implementation has generally rested on accommodation to constraints in the real world and on local preferences for such traditional objectives as community protection and even rehabilitation. However, common features of probation based on the justice model are (1) a greater focus on the offense than is the case in many probation departments, (2) the use of a reparative element, (3) the limiting of discretion, (4) close alignment with the court, (5) a view of probation as a sanction rather than as a suspension of punishment, and (6) the involvement of the local community. American probation has strong but not total support for the major precepts of the justice model. The move from treatment to offender aid, the structuring and monitoring of decisionmaking, and the new emphasis on the victim and community as client are supportive trends. However, trends such as the use of risk and needs assessment tools run counter to the model. Individual probation departments vary widely in their apparent receptivity to the principles of justice model probation. Where offender rehabilitation or community protection through crime prevention is the focus, justice model reforms are hindered. Although the model could try to accommodate the values and goals that appear to oppose its implementation, a better approach would be to implement the model fully in jurisdictions to which it is well suited. Thirty-seven references are listed.