Supportive parenting practices including autonomy granting and non-parental factors including adolescents’ connections to their communities are significantly associated with adolescent substance use outcomes; however, few longitudinal studies have considered both factors concurrently in nationally representative samples. Using longitudinal data from a nationally representative sample of adolescents in grades 7–12 (n = 12,139; 51% male), results indicated that community engagement significantly moderated the association between parental autonomy granting and substance use into emerging adulthood. Results also suggested that community disadvantage was a significant risk factor for adolescents’ substance use. These results further indicated that substance use among emerging adults was also high when accounting for prior levels of community engagement and parental-autonomy, and while controlling for substance use during adolescence.