This study investigates ethnic differences for 295,945 children and youth with an autism eligibility reported to the U.S. Department of Education (USDOE) by 49 states plus the District of Columbia. Data analyses used relative difference, risk index, and risk ratio (RR). Results indicate that 80% of states report underrepresentation across ethnicities, with Hispanic children underrepresented in 95% of states. Use of developmental delay label was significantly related to disproportionate representation for school-age population (F = 3.291, p = 0.046). Region of country yielded significant differences in RR for children classified as Asian (F = 3.532, p = 0.014) and Caucasian (F = 5.219, p = 0.002), for Black (F = 4.355, p = 0.005) and Caucasian (F = 2.840, p = 0.038) preschoolers, and for Asian (F = 5.676, p = 0.001) and Caucasian (F = 4.906, p = 0.002) youth. Policy, training, and programming implications of the data are discussed. (Contains 5 tables.)