Objectives: Advance care planning (ACP) specifies decision-making surrogates and preferences for serious illness or end-of-life medical care. ACP research has largely neglected sexual minority men (SMM), a population that experiences disparities in health care and health status. Methods: We examined formal and informal ACP among SMM ages 40+ in the Multicenter AIDS Cohort Study ( N = 1,071). Results: For informal ACP (50%), younger SMM and men with past cardiovascular events had greater odds of planning; single men had lower odds of planning. For formal ACP (39%), SMM with greater socioeconomic status had greater odds of planning; SMM who were younger, of racial/ethnic minority identities, who were single or in a relationship without legal protections, and who lacked a primary care home had lower odds of planning. Discussion: Findings warrant further exploration of both informal and formal planning. More equitable, culturally-humble engagement of SMM may facilitate access, uptake, and person-centered planning.