The benefits of integrating primary care and substance use disorder treatment are well known, yet true integration is difficult. We developed and evaluated a team-based model of integrated care within the primary care setting for HIV-infected substance users and substance users at risk for contracting HIV. Qualitative data were gathered via focus groups and satisfaction surveys to assess patients' views of the program, evaluate key elements for success, and provide recommendations for other programs. Key themes related to preferences for the convenience and efficiency of integrated care; support for a team-based model of care; a feeling that the program requirements offered needed structure; the importance of counseling and education; and how provision of concrete services improved overall well-being and quality of life. For patients who received buprenorphine/naloxone for opioid dependence, this was viewed as a major benefit. Our results support other studies that theorize integrated care could be of significant value for hard-to-reach populations and indicate that having a clinical team dedicated to providing substance use disorder treatment, HIV risk reduction, and case management services integrated into primary care clinics has the potential to greatly enhance the ability to serve a challenging population with unmet treatment needs.