This study explored the separate and interacting relations of family (cultural pluralism, promotion of mistrust) and school (equal treatment, intercultural learning) ethnic-racial socialization with cultural (heritage culture and German) identity among adolescents of immigrant descent. Analyses were based on survey data from 311 early to mid-adolescents in Germany (M[subscript age] = 13.85, SD = 1.82). Higher family cultural pluralism and intercultural learning at school were related to higher heritage culture identity, while higher equal treatment at school was related to lower heritage culture identity. Higher intercultural learning and equal treatment at school were related to higher German identity. Family promotion of mistrust had no direct relation to heritage culture or German identity. The interaction of family promotion of mistrust and equal treatment at school had relations to heritage culture but not to German identity. These findings expand our understanding of the complementary roles of family and school for supporting cultural identity development.