OBJECTIVE: Depression is common among patients in HIV care and is associated with worse HIV-related health behaviors and outcomes. Effective depression treatment is available, yet depression remains widely underdiagnosed and undertreated in HIV care. METHODS: As part of a multisite, randomized trial of depression treatment in HIV clinical care, the proportion of positive depression screens that resulted in study enrollment and reasons for nonenrollment were examined. RESULTS: Over 33 months, patients completed 9,765 depression screens; 19% were positive for depression, and of these 88% were assessed for study eligibility. Of assessed positive screens, 11% resulted in study enrollment. Nonenrollment after a positive screen was sometimes dictated by the study eligibility criteria, but it was often related to potentially modifiable provider- or patient-level barriers. CONCLUSIONS: Addressing patient- and provider-level barriers to engaging in depression treatment will be critical to maximize the reach of depression treatment services for HIV patients.