The two-year rule went into effect in 1984. To better understand how the policy affected the lives of those receiving methadone maintenance doses, researchers interviewed 143 clients at six month intervals over a period of two and a half years. Three types of clients were identified: the model client, the marginal client, and the stabilized client. Model clients comprised six percent of the population interviewed. They were conventional working-class and middle-class people who were gainfully employed and whose drug use was limited to methadone. Marginal clients comprised 25 percent of the study group, were members of the underclass, were unemployed, lacked job skills, and often had extensive criminal records. They were the least committed group to methadone maintenance and often caused trouble around the clinics. Stabilized clients comprised 69 percent of the study group, found methadone to be a stabilizing influence on their otherwise difficult lives, and were making attempts to avoid using other drugs. The study concludes that model clients fared well under the two-year rule policy, marginal clients continued to be involved in the heroin lifestyle, and stabilized clients suffered greatly because they depended on the methadone for stability but could not afford to pay for it. The article concludes with policy recommendations. 9 footnotes and 28 references.