As it has become more widely recognized that increasing numbers of people are living to progressively older ages, it is important to understand the nature of individual traits that promote resilience and welt-being in later life, to describe how these traits develop, to identify the factors that threaten and undermine their maintenance, and to elucidate the mechanisms that support and promote their growth. To have a knowledge base upon which to build intervention programs to improve and maintain well-being in later life, it is necessary to build understanding of what the multiple pathways are that lead to resilience, how these pathways may change, and what can be done to stop or forestall maladjustment and decline. Progress on these issues requires a greater understanding of process. In this article, we highlight theoretical areas of research on resilience and well-being that have received relatively little attention in previous work with older adults. We also identify unresolved methodological challenges associated with the measurement and analysis of within-person phenomena and elaborate on the implications of these challenges for process research in aging populations. Finally, we discuss future intervention directions to advance knowledge of resilience and positive health in later adulthood.