The Massachusetts DOC contracts with a forensic health organization to provide research-based, comprehensive sex offender treatment for male and female sex offenders. The program is based on a cognitive behavioral model that incorporates a relapse-prevention component to reduce the risk of recidivism. The program has three parts: (1) pretreatment; (2) core treatment; and (3) maintenance. Offenders enroll in pretreatment when they are approximately 6 years from their earliest possible release date. Pretreatment focuses on the concepts of sex offender therapy and prepares participants to deal with their sexual deviancy. Following satisfactory completion of the requirements of pretreatment, which include written assignments and class discussions, participants move on to core treatment, which relies on the principles of a therapeutic community. Core treatment involves primary therapy groups, psycho-educational classes, behavioral treatment, and community unit meetings. Treatment plans are customized to the unique treatment needs of each participant. Participants who successfully complete the structured program requirements of core treatment progress to the maintenance component, which is designed to prepare participants for release and treatment within the community. This phase of the program links offenders to community sex offender treatment providers. The DOC offers similar sex offender treatment and maintenance programming for women, which is designed to meet the unique needs of female offenders. Following release from prison, sex offenders are supervised in the community using two models: (1) the parole department’s Intensive Parole for Sex Offenders; and (2) the probation department’s Sex Offender Containment Program. Each is described and both boast zero recidivism rates for the hundreds of probationers and parolees that have come under their supervision since 1996.