The purpose of this study was to assess how the experience of stressful life changes might provide an opportunity for ego development in adulthood. The sample included 104 women in the early stage of the separation and divorce process; 91% of the sample was recontacted after 1 year had elapsed. Longitudinal analyses of the adaptation process supported the hypothesis that marital separation and divorce might be a disequilibrating life change, but one that might foster ego development. Those women who experienced this life change as disequilibrating but who made a successful adaptation by Time 2 showed a significant increase in ego level. Furthermore, those women who were high in adjustment at Time 1 but low in adjustment at Time 2 showed a theoretically consistent regression in ego level. Patterns of adaptation to life changes, their relationship to ego development, and the theoretical implications for Loevinger's model are discussed.