This chapter focuses on delivering effective interventions in institutional settings. The chapter begins with a discussion on the use of incarceration, its impact on recidivism, and a review of efforts to reduce the prison population in the United States. Next, assessment and classification within institutional settings is discussed, followed by the importance of treatment within these settings. Specific types of programs discussed include drug treatment programs, sex offender programs, general counseling programs, and educational/vocational programs. In addition to its focus on prisons, specific recommendations are made for jails and residential settings. The chapter concludes by addressing special considerations for providing services within these settings.