The organizational effectiveness of methadone maintenance treatment is qualitatively evaluated by analyzing levels of compliance and involvement with treatment programs for clients at three types of methadone clinics in the San Francisco Bay Area. Secondary analysis is used on longitudinal data collected from a project funded by the National Institute on Drug Abuse, "Injection Drug Users, Methadone Maintenance Treatment, and AIDS" (n = 233). This analysis rests on the theoretical model of clinics types differentiated by the clinic's style of control over clients. With a focus on the interaction between individuals and their institutional environments, the analysis compares three types of clinics: reformist, medical-model and libertarian. Reformist clinics exercise the most control over their clients and libertarians the least. Compliance with clinic rules is defined as changes in levels of drug use and involvement with clinic program is comprised of patterns of retention. While affiliation at all three clinic types reduces drug use, reasons for continued use vary substantially by clinic type. Variation is explained by a control balance approach to understanding responses to organizational type.