The number of offenders supervised in the community has grown significantly over the past few decades, whereas successful completions of probation and parole terms have been declining during the same time period. Data were collected on a random sample of 283 offenders who participated in an ISP between 2000 and 2003. Agency records, including supervision notes, violation reports, and other offender-related correspondence, were used to track offenders' sanction and reward histories during their participation in the program. Controlling for a number of variables, the study found that the use of both sanctions and rewards led to higher success rates. Administering rewards in proportionally higher numbers than sanctions produced the best results, especially when a ratio of four or more rewards for every sanction was achieved. Correctional administrators are encouraged to identify ideological obstacles that may impede the application of behavioral techniques and to carefully train and guide line staff in the use of sanctions and rewards. (Published Abstract)