The highly infectious Delta variant of COVID-19 is on the rise just as the school year begins. Vaccination is one of the most powerful tools to protect students and broader school communities. However, there is currently no authorized COVID-19 vaccine for children under 12. We must rely on other mitigation measures to protect them. In July 2021, the Centers for Disease Control and Prevention (CDC) and the American Academy of Pediatrics (AAP) both updated their guidance to recommend universal indoor masking for everyone in school, regardless of vaccination status, along with other mitigation measures. What masks should parents select to protect their children as they return to school?