This study examined individual, family, and peer religiosity, and religious community supportiveness as predictors of adolescent religious deidentification. The longitudinal study involved two waves of data, two years apart, from U.S. families (1,021 families; religious adolescents from 11-17 years of age), with measures of dimensions of religiosity at Time 1 and changes in religious identification from Time 1 to Time 2. Within each domain, at least one dimension of religiosity at Time 1 predicted religious deidentification at Time 2. Specifically, youth higher in individual, family, and peer religiosity, and religious community supportiveness, were less likely to leave religion. These relations were not moderated by religious affiliation. When using domain composite scores as predictors, individual and family religiosity uniquely predicted religious deidentification. Individual religiosity partially mediated relations of family religiosity, peer religiosity, and religious community supportiveness with religious deidentification. These results align with a relational developmental systems approach to religious deidentification.