Most understandings of successful aging are developed within a heteronormative cultural framework, leading to a dearth of theoretical and empirical scholarship relevant to lesbian, gay, bisexual, transgender, and queer (LGBTQ) older adults. This study explores the experiences of transgender persons who contemplate or pursue a gender transition in later life in order to develop culturally diverse conceptualizations of health and wellness in older age. Using the extended case method, in-depth interviews were conducted with male-to-female-identified persons (N = 22) who have seriously contemplated or pursued a gender transition past the age of 50. In addition, 170hr of participant observation was carried out at 3 national transgender conferences generating ethnographic field notes on the topics of aging and gender transitions in later life. Interpretive analyses suggest that many transgender older adults experience challenges to their gender identities that put their emotional and physical well-being at risk. Contemporary queer theory is used to understand these experiences and argue that greater attention to experiences of queer "failure" and negotiating "success on new terms" may be integral aspects of growth and development for transgender older adults. The Baby Boom generation is aging in a post-Stonewall, LGBTQ civil rights era, yet gerontology's approach to gender and sexual identity has largely been formulated from a heteronormative perspective. A framework for understanding older transgender persons' experiences informed by queer theory offers a new orientation for conceptualizing successful aging in the lives of marginalized gender and sexual minorities.