Civic engagement maintains the viability of democratic society and promotes positive outcomes for those who participate. Young adults' patterns of civic engagement differ according to the type of activity, yet little is known about the psychological mechanisms that lead to different types of participation. We tested the relationship between two types of sociopolitical beliefs (sense of agency and systems worldview) and two distinct forms of civic engagement: political involvement and community service. We hypothesized that agency would predict both forms of engagement and that systems worldview would moderate the relationship between agency and political involvement, but have little effect on community service. Using data from a racially diverse national sample of highly engaged young adults (n = 259), we conducted hierarchical linear multiple regression analyses and found that agency predicted both political involvement and community service. We found that systems worldview moderated the relationship between agency and both forms of civic engagement.