The study consists of two parts, (1) an evaluation of the effect of long-term parole supervision on methadone maintenance patient behavior, and (2) an evaluation of the impact of closing the Bakersfield, California methadone clinic in September 1976. The first study involves follow-up interviews with a sample of 136 males admitted to Los Angeles, San Bernardino and Orange Counties methadone programs during 1971-73 who had an average of 4-5 years remaining on parole under the California Civil Addict Program, and a matched sample of admissions to the same programs who were not on parole status. In addition a random sample of 100 admissions during the 1971-73 period is included. Retrospective data are collected from the time of first narcotic use to the time of interview on employment, drug use, criminal behavior and other variables. A urine sample is obtained at the time of interview. The second study involves follow-up interviews with all persons enrolled in the Bakersfield methadone clinic on June 30, 1976 (60 males and 39 females) and a comparison sample of 88 of those enrolled in the Tulare clinic on the same date. Since there was no other methadone clinic within 70 miles of Bakersfield, the large majority of patients did not transfer to other programs. Thus the closing of the clinic provides a unique opportunity to assess the costs and benefits of methadone maintenance via a natural experiment which avoids many of the methodological problems encountered in the evaluation of on-going programs. A modified version of the career history interview used in the first study is employed, and provides a detailed measure of the individual, social and economic impact of the termination of the Bakersfield clinic in comparison with the sample from the continuing Tulare program.