Impediments to inmate treatment effectiveness are the generally nontherapeutic environment of prisons, the severity of inmate problems, and program inadequacies. The Stay 'N Out program has largely overcome these obstacles. Criteria for selection into the program are a history of drug abuse, at least 18 years old, evidence of positive institutional participation, and no history of sex crimes or mental illness. Clients are housed in units separated from the general prison population but eat in the common dining room and attend morning activities with other inmates. Treatment is from 6 to 9 months. The early treatment phase involves observation and assessment of client needs and problem areas. Activities include morning and evening meetings, a daily seminar, peer counseling groups of 10 residents, an encounter group twice weekly, and an emotionality group that focuses on basic feelings. Proper use of rewards and punishments is critical to the effective operation to TC treatment. The staff has a balance of ex-offender and/or ex-addict paraprofessionals and a support network of formally trained professionals. The program has reduced recidivism rates and increased the length of time from release to arrest for those who do recidivate. 21 references.