The Key Extended Entry Program (KEEP) is the only known methadone treatment program for incarcerated opiate-dependent inmates in the United States. Initiated in 1987, KEEP performs approximately 18,000 detoxifications and 4,000 admissions for methadone treatment per year. Of those methadone treatment patients discharged to the community, mostly to outpatient KEEP programs, 74-80% report to their designated program. Recidivism rates reveal that 79% of KEEP patients were incarcerated again only once or twice during a recent 11-year period. Finally, KEEP data point to the importance of dedicating slots in the community for released inmates and maintaining them on sufficient blocking doses to eliminate the craving for heroin. About 6% of KEEP patients, some with mental illness have a high incidence of recidivism.