A Health Resources and Services Administration-Substance Abuse and Mental Health Services Administration collaboration was established to improve health outcomes for opiate-dependent HIV-infected patients through promotion of integrated models of HIV primary care and substance abuse treatment. The collaboration comprised 10 demonstration sites coordinated by a technical assistance/evaluation center that worked to refine planned interventions, address state-of-the-art treatment and policy issues relating to the use of buprenorphine opioid abuse treatment in HIV primary care settings, conduct local and multisite evaluations, and disseminate program findings. This article describes the goals and objectives of the collaborative as well as the interagency interactions and steps taken to establish the collaborative.