RecruitingBehavioural interventionThe Collaborative Care PrTNER StudyA randomized controlled trial to assess the ability of a Collaborative Care Prevention, Treatment, Navigation, Engagement, Resource (PrTNER) intervention to increase initiation of preexposure prophylaxis (PrEP) (for those at-risk for HIV) and decrease viral load (for those living with HIV) among young aged 15 to 29 through engagement in SU treatment.