In a pilot study, 130 methadone maintained subjects with a six-month history of good treatment performance were assigned randomly, for a one-year study period, to an experimental condition (once per month non-random urine screen, counseling session and doctor visit, two times per month methadone pick up, a quarterly true random urine screen, and participation in a diversion control program), or they were assigned to a control condition of staying under standard conditions for six months and then being transferred to the experimental condition for six months. Three out of four subjects (73%) completed the year in good standing with no differences between control and experimental conditions. Subject satisfaction was such that the Institutional Review Board judged that return to standard conditions would be a hardship. A Study of Medical Maintenance (SMM) continues and extends the pilot study with two protocols: (1) for new subjects and (2) for subjects entered from the pilot study. SMM requires a once per month random urine screen and extends the experimental condition to two years but is otherwise identical to the pilot study; 71 of 107 S's (66%) entered protocol 1 and are in good standing. Pilot subjects (N = 75) are holding their good performance, some for over four years. The reduced levels of services in these studies free up resources which can be applied to entering IDU's into treatment thereby contributing to a slowing of the HIV epidemic.