A case management model for adolescent substance abusers whose problems are severe enough to warrant residential treatment is presented, based on the experience of a demonstration project. The five integral functions of case management (assessment, planning, linking, advocacy, and support) are described within the framework of each phase of an adolescent's treatment program (screening, residential treatment, and continuing care). Detailed descriptions of case management activities and the philosophy underlying case management are addressed. The integrated client tracking and program evaluation monitoring system developed for the case management project is described, and evaluation data are presented. Among the advantages case managers are able to offer to the entire treatment process include encouragement of family involvement in the youth's recovery; providing support; tracking substance abuse relapse episodes following treatment; connecting the youth with school, work, and community resources; and helping youth to fulfill legal obligations.