We work from a stress and life course perspective to consider how stress affects trajectories of change in marital quality over time. Specifically, we ask whether stress is more likely to undermine the quality of marital experiences at different points in the life course. In addition, we ask whether the effects of adult stress on marital quality depend on childhood family stress experiences. Growth curve analysis of data from a national longitudinal survey (Americans' Changing Lives, N = 1,059 married individuals) reveals no evidence of age differences in the effects of adult stress on subsequent trajectories of change in marital experiences. Our results, however, suggest that the effects of adult stress on marital quality may depend on childhood stress exposure. Stress in adulthood appears to take a cumulative toll on marriage over time--but this toll is paid primarily by individuals who report a more stressful childhood. This toll does not depend on the timing of stress in the adult life course.