Men who have sex with men (MSM) and transgender women (TW) are key populations in the HIV epidemic. HIV status communication between sex partners can inform decisions regarding sexual behavior. MSM and TW were asked about HIV status communication with sex partners at baseline, 9- and 18-months. GEE models assessed associations with HIV status communication at baseline using prevalence ratios (PRs) and longitudinally using odds ratios (ORs). At baseline, those who had previously had an HIV test, disclosed their HIV status to 42 % of their sex partners. HIV status communication was associated with knowing their sex partner's HIV status at baseline (aPR 5.20) and longitudinally (aOR 1.86). HIV positivity at baseline was negatively associated with HIV status communication during follow-up (aOR 0.55). All reported aPRs and aORs have p < 0.05. Interventions promoting HIV status communication and more frequent HIV testing should be explored as current efforts are insufficient.