Data released by the Centers for Disease Control and Prevention (CDC) on Monday shows that vaccination rates for U.S. kindergartners declined during the 2025-26 school year. The report indicates that the share of children with vaccine exemptions rose to a record high of 4.2%, affecting an estimated 155,000 students nationally. This marks the fourth consecutive year that the national exemption rate has increased.
The decline follows a period of transition in federal health policy. Over the past 18 months, U.S. Health Secretary Robert F. Kennedy Jr. and other officials have sought to revise and reduce childhood vaccination guidance. Additionally, President Trump recently issued a call for revamped recommendations that would space out childhood shots into separate medical visits, a proposal that medical organizations, such as the American Academy of Pediatrics (AAP), stated is not supported by research.
According to the CDC, 92.4% of kindergartners received the required measles-mumps-rubella (MMR) vaccine last year, a slight decrease from the previous year and below the 95% threshold recommended by health experts to prevent outbreaks. Rates also fell for vaccines protecting against polio, chickenpox, and the combination shot for diphtheria, tetanus, and pertussis. The vaccination rate for hepatitis B remained steady, though experts noted this shot is typically administered shortly after birth.
The CDC reported that the increase in exemptions was driven largely by nonmedical reasons, with 41 states and the District of Columbia seeing a rise in opt-outs. Regional differences are significant; in Idaho, 17.5% of kindergartners had an exemption for at least one vaccine, while in Connecticut, the rate was less than 0.5%. In response to the data, the CDC issued a statement encouraging parents to discuss vaccination options with their doctors.
The scale of this shift involves hundreds of thousands of families and follows a significant change in how the federal government communicates health data. Since the start of the Trump administration last year, the CDC has moved from publishing detailed analytical reports in the Morbidity and Mortality Weekly Report to posting data online with brief statements. For families, this may result in less direct guidance from federal agencies regarding the timing and necessity of specific shots. The push to space out vaccines into separate medical visits would, if implemented by individual providers, increase the number of doctor visits and co-pays required for a child to be considered fully vaccinated for school attendance.
The knock-on effects are already being observed in public health systems, as the U.S. is currently experiencing its highest number of measles cases since 1991. Because unvaccinated children are not distributed evenly across the country, localized outbreaks may place increased strain on regional healthcare facilities and school districts, which rely on attendance mandates to maintain classroom stability. While infant hepatitis B rates remain stable for now, health experts suggest changes in federal recommendations may not be reflected in kindergarten data for several more years. The CDC continues to monitor these trends as the current school year begins, but no new federal mandates or deadlines for vaccination schedule changes have been announced.