Borrowing from the literature on religion and deviance, the concept of moral communities is applied to religious and secular postsecondary education to explain institutional influences on student religious participation. Results from nationally representative panel data indicate that students attending Catholic and mainline Protestant affiliated institutions decline in religious participation at a faster rate than students attending evangelical institutions or students attending nonreligious public colleges and universities. This finding is consistent with Catholic and mainline Protestant institutions less successfully providing a shared moral order that legitimates religious language, motive, and behavior when compared to conservative Protestant colleges. At the same time, the religious and ethnic pluralism that activates minority religious identity at nonreligious public institutions is also less likely to be present on Catholic and mainline Protestant college campuses. Additional results indicate that evangelical students' religious participation declines while attending Catholic colleges and universities, while Catholic students increase their participation while attending evangelical institutions. The religious composition of students may act to alter friendship networks, and thus participation rates, on these campuses, although further research is necessary to validate the proposed institutional mechanisms.