In this study the investigators will extend the use of the DCE method to design an HIV testing intervention that is matched to the specific preferences of two high-risk populations and to establish, in a pragmatic randomized controlled trial, whether a Preference-Based HIV Counseling and Testing (PB-HCT) intervention increases uptake of HIV testing. In short, the investigators are adapting concepts from health and behavioral economics, marketing, and patient-centered care to apply a groundbreaking, client-focused perspective to the context of HIV testing.