This study is a randomized strategy evaluation of the feasibility, effectiveness, and cost-effectiveness of rapid ART initiation. Outpatient, non-pregnant, HIV-positive adults who come to a South African clinic for an HIV test, consent to study participation, and are eligible for ART will be randomized 1:1 to rapid ART initiation or to standard care. Those who are assigned to rapid ART initiation will have the possibility of receiving their first dose of ARVs as early as the same day, while those who are assigned to standard care will follow the clinic's usual procedures for starting ART. Rapid ART initiation for HIV-positive pregnant women, which has recently become the standard of care in South Africa, will also be assessed in a programmatic evaluation conducted alongside the randomized evaluation, with a retrospective comparison group. The primary study outcome for non-pregnant adults will be remaining alive, in care and virally suppressed 10 months after having a positive HIV test at the study site or making a first HIV-related visit. The primary study outcome for pregnant women will be adherence to ART until delivery. The cost effectiveness of the rapid initiation strategy will be assessed as the cost per patient achieving the primary outcome for each population.