This study was a process evaluation of Pennsylvania's two Residential Substance Abuse Treatment (RSAT) programs in their first year of implementation. These programs were maintained through the joint management of the state Department of Corrections (DOC), Board of Probation and Parole, Pennsylvania Commission on Crime and Delinquency, and two private sector providers that operated the programs. Opened in early 1998 in two correctional facilities for men, each of these programs could serve up to 60 male technical parole violators (TPVs) with a history of substance abuse. Instead of the nine- to 36-month terms typical for parolees recommitted for violations, RSAT participants served six months in prison-based intensive therapeutic communities (TCs), followed by six months of aftercare in a DOC-sponsored Community Corrections Center (CCC), similar to a halfway house. Both programs took a cognitive-behavioral approach to drug treatment. This study focused on the prison-based component of the RSAT programs. It examined the extent to which components of RSAT treatment were in place and the integrity of program operations. Interviews for this study were conducted between February and December 1998. At intake, program staff interviewed RSAT participants (Part 1, Intake Data), and Vera Institute of Justice onsite researchers conducted participant interviews upon exit (Part 2, Exit Data). Through December 31, 1998, 160 intake interviews and 77 exit interviews with program graduates were administered.