This is a phase 1 clinical trial to evaluate the safety and pharmacokinetics of the highly neutralizing anti-human immunodeficiency virus-1 monoclonal antibodies 3BNC117 and 10-1074, when given in combination, in human immunodeficiency virus (HIV)-uninfected individuals. This study is intended to support the development of the combination of 3BNC117 and 10-1074 mAbs for use as prophylaxis against HIV infection in healthy HIV-uninfected individuals at risk for HIV infection.