Black sexual minority men (SMM) face numerous challenges, including adverse childhood experiences, socioeconomic marginalization, and intersectional stigma, all of which affect their experiences, behaviors, and health outcomes. These and other experiences can change across the lifespan, as can the contexts in which they occur. By necessity, assessing the effects of these experiences requires a Life Course perspective that can address the complex interactions of biological, social, psychological, and structural factors that shape population health trajectories. In this chapter, we review Life Course concepts and present two formidable issues that can affect scientific understanding of Black SMM’s experiences and outcomes. The first issue addresses the conceptual “fit” of Life Course measures on the lives of Black SMM. The second issue addresses whether existing studies use assessment instruments that align with a Life Course approach or help reinforce its basic principles. Included in this section is an Appendix detailing measurement approaches used in Life Course studies and that were conducted with Black SMM or sexual minorities more generally. Although the studies discussed here are largely U.S.-based, they offer a foundation for addressing cross-cultural instruments to study Black SMM globally. The chapter concludes with future directions to address measurement gaps in the literature and identifies several ways to engage in theoretical, methodological, and psychometric refinement that will help the field learn more about the factors that influence Black SMM’s lives globally.