This document discusses new options for HIV prevention through the use of antiretroviral therapy (ART). Observational studies and the HPTN 052 clinical trial showed that ART can significantly decrease the risk of transmitting HIV, with a 96% reduction in risk seen in the HPTN 052 trial. However, real-world adherence to lifelong ART may be challenging and is not as high as was achieved in HPTN 052 through intensive support strategies. U.S. guidelines now recommend ART for all HIV-infected individuals, but limitations remain regarding how well ART prevents transmission through different risk behaviors or in situations where adherence is imperfect.