Pretrial services were just starting in the Federal system as a demonstration project in 10 courts in 1975, but expanded nationwide during the 1980s to become fully implemented in every district court. Skepticism about the effectiveness of the rehabilitation model and indeterminate sentencing was already growing in 1975, but few could have foreseen the sweeping changes brought about by the Comprehensive Crime Control Act of 1984. The replacement of rehabilitation by a "just deserts" model and the phasing out of parole marked a definitive end to an era that began with such optimism for the ideals of rehabilitation. Now, sentencing guidelines and mandatory minimum sentences set the tone, and the probation officer in the caseworker role no longer predominates. One impact of the transformation to the crime control model is that most offenders now serve prison terms before they are supervised in the community by Federal probation officers. Where once there was a simple officer/clerk dichotomy, there are now a variety of officer specialties to match the growing complexity of the work, including sentencing guidelines, substance abuse treatment, mental health treatment, and electronic monitoring. Decentralization of personnel and financial management has given rise to a variety of administrative support specialties as well, including budget and fiscal reporting, procurement, property management personnel administration, accounting, and contracting. Further, technology has radically changed daily operations. This article briefly describes the milestones in the history of the Federal probation and pretrial services system from 1975 to the present. 2 tables and 17 references