Children's hospitals responded to COVID-19 by limiting nonurgent healthcare encounters, conserving personal protective equipment, and restructuring care processes to mitigate viral spread. We assessed year-over-year trends in healthcare encounters and hospital charges across US children's hospitals before and during the COVID-19 pandemic. We performed a retrospective analysis, comparing healthcare encounters and inflation-adjusted charges from 26 tertiary children's hospitals reporting to the PROSPECT database from February 1 to June 30 in 2019 (before the COVID-19 pandemic) and 2020 (during the COVID-19 pandemic). All children's hospitals experienced similar trends in healthcare encounters and charges during the study period. Inpatient bed-days, emergency department visits, and surgeries were lower by a median 36%, 65%, and 77%, respectively, per hospital by the week of April 15 (the nadir) in 2020 compared with 2019. Across the study period in 2020, children's hospitals experienced a median decrease of $276 million in charges.