This research uses data from waves I and IV of the National Longitudinal Study of Adolescent Health (Add Health, N = 9,631) to consider whether and how family instability in early or later childhood affects college enrollment and completion of a Bachelor's degree by age 24. Explanatory factors include maternal selection into unstable unions, household resources available in adolescence, and adolescents' academic achievement, behavior, and attitudes in high school. The association of later family instability with college enrollment and completion is largely explained by household resources in adolescence. The association of early family instability with college enrollment is partially explained by each set of factors, and its association with college completion, given enrollment, is explained by pre-existing maternal characteristics. The results demonstrate that early family instability has enduring consequences for eventual status attainment and that the mechanisms that connect family instability to educational outcomes vary by the timing of family structure change.