The preliminary report of the Center's multiphase effort to document the effects of the Probation Division's aftercare program for drug-dependent federal offenders. The author reviews the operation of the program in a sample of ten probation districts. He describes the program's general approach; various characteristics of offenders in the program; services planned for and received by offenders; and adjustment experiences of offenders in aftercare, including resumed or continued drug use, new arrests and convictions, and technical violations.