The United States is facing culture gaps between students and teachers in schools. Although the U.S. school-age population is racially, culturally, and linguistically diverse, the teachers are predominantly White. This article investigates whether assignment to same-race teachers affects students' math and reading achievement growth in early elementary grades. The article also examines if overall teacher diversity in schools moderates the relationship between student-teacher ethnoracial match and achievement growth. This study finds that assignment to same-race teachers has no effect on minority students' math and reading achievement growth between kindergarten and 3rd grade. However, the overall teacher diversity in school does affect whether minority teachers are effective educators for minority students. This interactive effect is significant for math and reading achievement growth among Hispanic students. Hispanic teachers are most effective as educators for Hispanic students when these teachers also teach in schools with greater teacher diversity. Hispanic teachers are least effective as educators for Hispanic students when these teachers work in schools with low teacher diversity.