As the HIV epidemic has evolved to become a chronic, treatable condition the focus of HIV care has shifted from the inpatient to the outpatient arena. The optimal structure of HIV care in the outpatient setting is unknown. Using the HIV Research Network (HIVRN), a federally sponsored consortium of 21 sites that provide care to HIV-infected individuals, this study attempted to: (1) document key features of the organization of care in HIVRN adult clinics and (2) estimate variability among clinics in these parameters. A cross-sectional survey of adult clinic directors regarding patient volume, follow-up care, provider characteristics, acute patient care issues, wait times, patient safety procedures, and prophylaxis practices was conducted from July to December 2007. All 15 adult HIVRN clinic sites responded: 9 academic and 6 community-based. The results demonstrate variability in key practice parameters. Median (range) of selected practice characteristics were: (1) annual patient panel size, 1300 (355-5600); (2) appointment no-show rate, 28% (8%-40%); (3) annual loss to follow-up, 15% (5%-25%); (4) wait time for new appointments, 5 days (0.5-22.5), and follow-up appointment, 8 days (0-30). The majority of clinics had an internal mechanism to handle acute patient care issues and provide a number of onsite consultative services. Nurse practitioners and physician assistants were highly utilized. These data will facilitate improvements in chronic care management of persons living with HIV.