Through this study, approximately 1,350 HIV-infected individuals who meet criteria for opioid dependence will be selected by eleven model demonstration projects located in ten HIV care centers across the U.S. Information on patients’ drug use, HIV health status, service utilization, quality of life, and satisfaction with services as well as information about providers’ practices and attitudes towards treating drug dependent patients will be collected through face-to-face interviews, audio computer-assisted self-interviewing, written surveys, and chart abstractions. These data will be used to help replicate effective programs that integrated HIV care and drug treatment and to improve the care of HIV-infected opioid dependent individuals.