Though federal alternative to incarceration (ATI) programs have proliferated at the grass-roots level, to date there have been no empirical studies of how effective these programs are in the federal system. This article describes results of a study that sought to quantify the pretrial services' measures of new criminal arrests, failures to appear, and other violations of court-ordered conditions of release, i.e., technical violations. The study also sought to quantify defendants' improvements in illicit drug use and employment and, among defendants whose cases have been disposed by the courts, the sentences the courts imposed.