This analysis describes key HIV-related outcomes from the LEGACY study, which followed a diverse cohort of trans adults receiving primary care at two large, federally qualified health centers in the northeast US.  Investigators assessed whether gender affirming hormone therapy (GAHT) was associated with reduced rates of HIV seropositivity and viral non-suppression in the past 12 months.  GAHT was delivered per established standards, and HIV testing was performed as clinically indicated per medical provider determination.  De-identified health record data were extracted across seven years of follow-up.  Overall, rates of HIV seropositivity were 9.1% in 2013 and 6.9% in 2019, and viral non-suppression decreased: 22.4% of participants with HIV in 2013 were not suppressed compared to 15.7% in 2019.  In multivariate analyses, participants with a current GAHT prescription had significantly lower risk of HIV seropositivity: factors associated with higher risk included being in an older age group; being a transgender woman or non-binary assigned male at birth; identifying as a racially or ethnically minoritized group; and having public or no insurance.  Among participants with HIV, people with current GAHT prescription had significantly lower risk of viral non-suppression: associated factors included being in older age groups; being a transgender woman; and living at 100−199% FPL and 200–299% FPL (vs. 0–99% FPL).