Abstract Introduction: Sexual minority women (SMW) are a group that experience health disparities, including disparities in cancer risk, according to the recent Institute of Medicine report on Lesbian, Gay, Bisexual and Transgender health. Differences in SMW's psychosocial functioning, and an examination of how psychosocial concepts cluster in this group, could inform us about their health disparities. Individual psychosocial concepts can be clustered to represent underlying factors that function as health indicators. Cluster patterns and function could differ among disparities groups like SMW due to exposures to minority stress. Minority stress is germane here because it influences the individual concepts that comprise clusters. SMW's exposure to minority stressors such homophobia, and prejudice and discrimination, may influence self esteem, stress, happiness, and social functioning. A first step in understanding the health disparities among SMW, could be to examine psychosocial clustering patterns and cluster associations with health outcomes, among this group. The current study sought to investigate the form and function of psychosocial clusters among SMW and heterosexual women (HW) participating in a population-based study of health and aging. The first objective was to explore and compare how psychosocial concepts cluster among these two groups of women. The second objective was to test for associations between clusters and SMW's physical and mental health compared to HW. Methods: This study used data from the National Social Life Health and Aging Project, a U.S., population-based, sample of 1550 women, aged 57–89. This included 1369 HW and 62 SMW. Hierarchical cluster analysis was used to identify the existence of clusters from nine psychosocial concepts: happiness, self esteem, stress, loneliness, emotional support from family, emotional support from friends, number of close relatives, number of close friends, number of social connections on a social network roster. Multivariate linear regression was used to test for significant associations between clusters and physical health, measured with a chronic disease comorbidity index, and mental health, measured with the, Center for Epidemiological Studies—Depression, scale. Results: Hierarchical cluster analysis revealed differences according to sexual orientation. Among HW, a two-cluster solution emerged: A Well-being Cluster, comprised of happiness, stress, loneliness, and self esteem; and a Social Cluster, comprised of all five of the social concepts. Among SMW, a three-cluster solution emerged: a Stress Cluster, comprised of, loneliness, self esteem and stress; a Social Cluster comprised of, number of close relatives, number of social connections on a social network roster, number of close friends, and emotional support from family; and a Friendship Cluster, comprised of happiness and emotional support provided by friends. Among HW, the Well-being Cluster was significantly associated with physical health (p < .001) and mental health (p < .001). Among SMW, the Stress Cluster was significantly associated with physical health (p = .04) and mental health (p< .001). Conclusion: Hierarchical cluster analysis made it possible to consider how psychosocial concepts cluster empirically and relate to health. We identified differences in psychosocial clusters among HW and SMW and determined significant associations between clusters and health among both groups. These results extend our understanding about SMW health by finding evidence for differences in psychosocial clustering patterns and by relating these differences to health outcomes. These findings are significant as they may highlight the most important components for enhancing SMW's health and reducing health and cancer disparities. Citation Information: Cancer Epidemiol Biomarkers Prev 2011;20(10 Suppl):B25.