Using nationally representative data in the US, the estimated ASD prevalence was 3.14% among children and adolescents in the US in 2019 and 2020. This finding was higher than the reported prevalence from the NHIS in 2014 to 2016 (2.47%),2 Autism and Developmental Disabilities Monitoring Network in 2018 (2.30%),4 and National Survey of Children’s Health in 2016 (2.50%).3 The estimated prevalence was also higher than that reported in other countries and geographical areas in previous years. Chiarotti and Venerosi6 reviewed ASD prevalence estimates published since 2014, which ranged from 0.42% to 3.13% in Europe, 0.11% to 1.53% in the Middle East, and 1.41% to 2.52% in Australia. The prevalence of ASD is higher in boys than in girls, and a significant difference was found in children with different family economic status in this study. We found the prevalence of ASD increased from 2014 to 2016, decreased from 2016 to 2017, and then increased again from 2017 to 2020.