Objectives. To determine whether intersectional stigma is longitudinally associated with biopsychosocial outcomes. Methods. We measured experienced intersectional stigma (EIS; ≥ 2 identity-related attributions) among sexual minority men (SMM) in the United States participating in the Multicenter AIDS Cohort Study. We assessed longitudinal associations between EIS (2008‒2009) and concurrent and future hypertension, diabetes, dyslipidemia, antiretroviral therapy adherence, HIV viremia, health care underutilization, and depression symptoms (2008‒2019). We conducted causal mediation to assess the contribution of intersectional stigma to the relationship between self-identified Black race and persistently uncontrolled outcomes. Results. The mean age (n = 1806) was 51.8 years (range = 22-84 years). Of participants, 23.1% self-identified as Black; 48.3% were living with HIV. Participants reporting EIS (30.8%) had higher odds of hypertension, dyslipidemia, diabetes, depression symptoms, health care underutilization, and suboptimal antiretroviral therapy adherence compared with participants who did not report EIS. EIS mediated the relationship between self-identified Black race and uncontrolled outcomes. Conclusions. Our findings demonstrate that EIS is a durable driver of biopsychosocial health outcomes over the life course. Public Health Implications. There is a critical need for interventions to reduce intersectional stigma, help SMM cope with intersectional stigma, and enact policies protecting minoritized people from discriminatory acts. (Am J Public Health. 2022;112(S4):S452-S462. https://doi.org/10.2105/AJPH.2022.306735).