In the US, methadone maintenance is restricted by federal and state regulations to large specialized clinics that serve fewer than 20% of the heroin-dependent population. In Europe, Canada, and Australia, primary health care providers already are utilized widely as methadone prescribers. In preparation for a limited study of office-based methadone treatment in New York City, 71 providers from 11 sites were surveyed about their willingness to prescribe methadone in their office-based practices. Of the 71, 85% had methadone-maintained patients who came to their practice for other care. One-third felt knowledgeable enough to prescribe methadone, and 66% said they would if given proper training and support (88% among AIDS care providers). Half expressed concern that they might be unable to meet the multiple needs of these patients. With additional training and ancillary support, the 47 providers willing to become methadone providers could serve, at 10-20 patients each, 470-940 patients, a population the size of 3-5 average methadone clinics.