Rates of diagnosed autism spectrum disorder have risen steadily since 2000, increasing from an overall prevalence of 6.7 per 1,000 children in 2000 to 23 per 1,000 in 2018 and 27.6 per 1,000 in 2020, according to results of the Autism and Developmental Disabilities Monitoring (ADDM) Network surveillance study in the March 24 Morbidity and Mortality Weekly Report. Prevalence was found to be nearly four times higher in boys than in girls. Earlier surveillance studies found prevalence in White children to be 50% higher than in children in other ethnic groups, but by 2016 the rates had become even. However, in 2020, for the first time, rates were lowest in White children (24.3) compared with Black (29.3), Hispanic (31.6), and Asian/Pacific Islander (33.4) children. In a separate report, the ADDM Network notes that beginning in March 2020, autism spectrum disorder evaluations and identifications dropped, due to the COVID-19 pandemic. Considering the critical importance of early intervention, this disruption in identification of autism could have serious long-term consequences for children.