While prison-initiated methadone maintenance treatment is effective, it is largely unknown as to what patient and program factors are related to outcomes. These issues were studied in a secondary analysis of data from 67 male prerelease prison inmates with preincarceration heroin addiction. Three outcomes are examined: completed prison treatment; completed 1 year of community treatment; and number of days in community treatment. Being employed (p=.045) during the 3 years prior to index incarceration was significantly and positively related to community treatment completion. Increased frequency of urine tests taken was significantly associated with a greater number of days in community treatment (p less than .001). Limitations, policy implications, and directions for future research are discussed. Abstract published by arrangement with Taylor and Francis.