Purpose of the Study: Good health and well-being in later life are central issues for public health. Retirement presents an opportunity to intervene to improve health and well-being, as individuals may adjust associated lifestyle behaviors. However, there is little evidence about how well-being is experienced in the context of increasingly diverse retirement transitions. Our objectives were to explore (a) views on health and well-being through retirement transitions and (b) acceptability of intervening in this period. Design and Methods: Qualitative study involving 48 workers/retirees, aged 53-77 years of diverse socioeconomic status, were recruited from urban and rural areas in North East England. Data were collected iteratively through focus groups (n = 6), individual interviews (n = 13), interviews with couples (n = 4), using the constant comparative method. Analysis was informed by theories of the Third Age and Sen's capabilities approach. Results: Diverse retirement transitions were shaped by unanticipated events. Central to well-being was the "capability" to utilize resources to achieve desirable outcomes. Participants rejected a "later life" identity, associating it with decline, and an uncertain future. Implications: Lifestyle interventions that address challenges within the retirement transition may be acceptable. Inducements to change behavior based on possible long-term outcomes may be less appealing. Providing assistance to use resources to address personal goals may be central to effective interventions.