PROJECT SUMMARY Transgender and gender diverse (TGD) people in the United States (US) experience significant health disparities throughout the life course relative to cisgender people. While extensive community-based research drawn from convenience samples and a burgeoning body of research using population-level data has assessed the healthcare utilization of TGD individuals, much of this research has focused on younger TGD people. Little national data exist on the health of older TGD people (i.e., 55 and older). Older adults, regardless of gender identity, are at increased risk of developing comorbidities that burden the healthcare system. TGD older adults are expected to be at even higher risk of developing multiple, concurrent health problems than cisgender people due to the stigma-related stress they experience throughout their lives. Further, like all people, TGD people require routine care and, often acute and post-acute care as they age; however, TGD individuals also have unique medical gender affirmation needs (e.g., hormones or surgery) and a dearth of research has explored the ways in which the use of these services shape older TGD people's use of other routine and acute care. The long-term goal of this research agenda is to improve healthcare quality and ultimately the health of older TGD people. The overall objective of this study is to create a comprehensive understanding of the comorbidities and healthcare use of older TGD adults. Consistent with NOT-MD-19-001: “Research on the Health of Sexual and Gender Minority (SGM) Population,” we propose to do use novel algorithms to identify a sample of 30,000+ older TGD people in Medicare data and follow their outcomes across 10 years of outpatient, acute- and post-acute claims and assessment data. We will also link Medicare data to state-level data and use qualitative methods to understand the multilevel factors that shape health outcomes for older TGD adults. To achieve these goals, we propose the following Aims: 1) To describe the prevalence and incidence of single and comorbid chronic conditions among TGD Medicare beneficiaries and to compare the healthcare utilization of TGD and cisgender beneficiaries; 2) To understand how individual, healthcare system, and community factors influence health and healthcare use of older TGD adults relative to older cisgender adults; and 3) To contextualize the quantitative findings by qualitatively assessing (via patient and provider interviews) the individual, healthcare system, and community-level barriers and facilitators to optimal health and healthcare utilization for older TGD adults that can be addressed in future multilevel interventions. This project is innovative because we will use datasets, methods, and outcomes that have not been previously applied to understanding the health of the older adult TGD population. This work will have a significant impact as it will yield novel, clinically-important, and policy-relevant evidence about how older ...