Black sexual minority men (BSMM) and Black transgender women (BTW) have disproportionately high HIV prevalence, making HIV testing critical for treatment and prevention. Racism and homophobia may be barriers to testing among BSMM/BTW, particularly in the context of previous incarceration. We analyzed a subsample (n = 655) of HIV-negative, previously incarcerated BSMM/BTW in the HIV Prevention Trials Network 061 study, generating prevalence ratios and interaction terms testing associations between experienced racism and homophobia with past-year HIV testing. Both racism (aPR = 0.83, 95% CI [0.70, 0.98]) and homophobia (aPR: 0.68, 95% CI [0.48, 0.98]) were associated with lower testing, although their interaction was associated with unexpectedly higher testing (Interaction aPR = 1.77, 95% CI [1.25, 2.49]). Among BSMM/BTW with a history of incarceration, racism and homophobia are barriers to HIV testing. Positive interactions between racism and homophobia could be explained by numerous factors (e.g., resilience, coping) and warrants further study.