OBJECTIVES: Describe population-based rates and risk factors for pediatric severe coronavirus disease 2019 (COVID-19) (ie, ICU admission, invasive mechanical ventilation, or death). METHODS: During March 2020 to May 2021, the COVID-19-Associated Hospitalization Surveillance Network identified 3106 children hospitalized with laboratory-confirmed severe acute respiratory syndrome coronavirus 2 infection in 14 states. Among 2293 children primarily admitted for COVID-19, multivariable generalized estimating equations generated adjusted risk ratios (aRRs) and 95% confidence intervals (CIs) of the associations between demographic and medical characteristics ed from patient electronic medical records and severe COVID-19. We calculated age-adjusted cumulative population-based rates of severe COVID-19 among all children. RESULTS: Approximately 30% of hospitalized children had severe COVID-19;0.5% died during hospitalization. Among hospitalized children aged <2 years, chronic lung disease (aRR: 2.2;95% CI: 1.1-4.3), neurologic disorders (aRR: 2.0;95% CI: 1.5-2.6), cardiovascular disease (aRR: 1.7;95% CI: 1.2-2.3), prematurity (aRR: 1.6;95% CI: 1.1-2.2), and airway abnormality (aRR: 1.6;95% CI: 1.1-2.2) were associated with severe COVID-19. Among hospitalized children aged 2 to 17 years, feeding tube dependence (aRR: 2.0;95% CI: 1.5-2.5), diabetes mellitus (aRR: 1.9;95% CI: 1.6-2.3) and obesity (aRR: 1.2;95% CI: 1.0-1.4) were associated with severe COVID-19. Severe COVID-19 occurred among 12.0 per 100 000 children overall and was highest among infants, Hispanic children, and non-Hispanic Black children. CONCLUSIONS: Results identify children at potentially higher risk of severe COVID-19 who may benefit from prevention efforts, including vaccination. Rates establish a baseline for monitoring changes in pediatric illness severity after increased availability of COVID-19 vaccines and the emergence of new variants. [ FROM AUTHOR] Copyright of Pediatrics is the property of American Academy of Pediatrics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)