CDC guidance for K–12 schools on steps during measles exposures, including exclusion periods for those lacking evidence of immunity.
“Exclude students and staff without evidence of immunity for up to 21 days after last exposure.”
Primary source: https://www.cdc.gov/measles/downloads/measles-checklist-K12-schools.pdf
Page prepared October 21, 2025. If this link changes, search the publisher site for the most recent version.