A 26-year-old woman is evaluated 48 hours after a sexual exposure to HIV. She is started on dolutegravir plus tenofovir DF-emtricitabine for HIV nonoccupational postexposure prophylaxis (PEP), and she completes a 28-day course of treatment. Her baseline HIV-1/2 antigen-antibody test was negative, as were serologic tests for hepatitis B virus (HBV), hepatitis C virus (HCV), and syphilis. Baseline nucleic acid amplification tests (NAATs) for Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis were negative. Five weeks after starting the HIV nonoccupational PEP, she returns for a follow-up visit and reports that she feels well.