The project will have two tracks, one for participants who are currently taking elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate or E/C/F/tenofovir alafenamide (E/C/F/TDF or E/C/F/TAF) single-tablet regimen* (STR) (Track A) and one for participants who will begin therapy with E/C/F/TDF or E/C/F/TAF STR during the study (Track B).