Abstract By 2030, there will be nearly six million sexual and gender minority (SGM) older adults aged 60 and older in the U.S. who identify as lesbian, gay, bisexual and transgender. Approximately 350,000 SGM older adults in the U.S. currently have Alzheimer?s disease and related dementias (ADRD), with projections nearing one million by 2030. Yet, almost nothing is known about the prevalence or risk of ADRD in SGM older adults without HIV/AIDS. This proposal will focus on the epidemiology and risk of ADRD in SGM older adults. The first aim of this proposal is to characterize the epidemiology and risk of ADRD in a population-based sample of SGM older adults and compare the prevalence and incidence of ADRD in SGM older adults to their heterosexual peers. The second aim will focus on identifying risk and protective factors for ADRD in SGM older adults, and to estimate the population attributable risk of depression and socioeconomic status (e.g., income and education) on ADRD. The third aim will involve primary data collection in a community-based sample of SGM older adults in order to investigate the relationship between risk and protective factors and cognition, including memory and executive function. This proposal incorporates several innovations that will allow me to evaluate the epidemiology and risk of cognitive impairment and ADRD in SGM older adults: 1) this will be the first study of the epidemiology and associated risk and protective factors for cognitive impairment and ADRD in SGM older adults; 2) it leverages the largest longitudinal dataset in the nation, Research Program for Genes Environment and Health (RPGEH), with data on the physical and psychosocial health of SGM older adults; and 3) it involves a novel investigation of factors that may be associated with memory and executive function impairment in SGM older adults. To successfully complete this research, I propose three training aims: 1) advanced statistical modeling of ADRD risk and protective factors; 2) epidemiology of SGM aging and health disparities; and 3) measurement and analysis of cognitive aging. This career development award ultimately will result in the submission of a R01 to develop a future multi-site epidemiological study of cognitive aging and ADRD in SGM older adults. Given that nothing is currently known about ADRD risk in this population, this work is necessary to promote early detection; to develop culturally relevant screenings and targeted preventative interventions to decrease ADRD risk in SGM older adults; and to improve the care and quality of life of this vulnerable and understudied population.