American Indians are disproportionately burdened by alcohol-related problems. Yet, research exploring predictors of alcohol use among American Indians has been limited by cross-sectional designs and reservation-based samples. Guided by a life course developmental perspective, the current study used a subsample of American Indians (n=927) from the National Longitudinal Study of Adolescent Health (Add Health) to explore alcohol use (current drinking, usual number of drinks, and binge drinking) among this population. We examined whether adult social roles (i.e., cohabitation, marriage, parenthood, college enrollment, and full-time work) were linked to the rise and fall of alcohol use. Multi-level models demonstrated that adult social roles were linked to alcohol use at the within- and between-person levels. Becoming a parent was linked to a lower likelihood of being a current drinker, fewer alcoholic drinks, and less frequent binge drinking. Transitioning to full-time work was associated with a higher likelihood of being a current drinker and more frequent binge drinking. Results point to the importance of exploring within-group trajectories of alcohol use and highlight the protective and risky nature of adult social roles among American Indians.