Interim Methadone Maintenance, also known as Interim Maintenance or IM, is a simplified methadone treatment program for opioid-dependent adults who are on waiting lists for comprehensive methadone treatment. IM consists of a daily, individually determined methadone dose, administered by a nurse, plus emergency counseling for up to 120 days. U.S. Federal regulations permit methadone treatment programs (MTPs) to provide IM to adults who seek treatment but, due to limited program capacity, cannot be admitted within 14 days. The regulations specify that (1) only public or nonprofit MTPs can provide IM; (2) patients receive counseling with IM only for emergencies or during times of crisis (e.g., serious medical problem, relationship issues, temporary loss of housing), although this occurs on an infrequent basis; and (3) patients must undergo limited drug testing. IM aims to facilitate entry into MTPs and reduce heroin use and criminal behavior by capitalizing on the motivation of the individual seeking treatment and providing help at the time of the request.