Abstract Background Mortality remains elevated among Black versus White adults receiving human immunodeficiency virus (HIV) care in the United States. We evaluated the effects of hypothetical clinic-based interventions on this mortality gap. Methods We computed 3-year mortality under observed treatment patterns among >40 000 Black and >30 000 White adults entering HIV care in the United States from 1996 to 2019. We then used inverse probability weights to impose hypothetical interventions, including immediate treatment and guideline-based follow-up. We considered 2 scenarios: “universal” delivery of interventions to all patients and “focused” delivery of interventions to Black patients while White patients continued to follow observed treatment patterns. Results Under observed treatment patterns, 3-year mortality was 8% among White patients and 9% among Black patients, for a difference of 1 percentage point (95% confidence interval [CI], .5–1.4). The difference was reduced to 0.5% under universal immediate treatment (95% CI, −.4% to 1.3%) and to 0.2% under universal immediate treatment combined with guideline-based follow-up (95% CI, −1.0% to 1.4%). Under the focused delivery of both interventions to Black patients, the Black–White difference in 3-year mortality was −1.4% (95% CI, −2.3% to −.4%). Conclusions Clinical interventions, particularly those focused on enhancing the care of Black patients, could have significantly reduced the mortality gap between Black and White patients entering HIV care from 1996 to 2019.