US kindergarten vaccination rates dip, exemptions hit record high

New federal data released Monday shows that U.S. kindergarten vaccination rates slipped for another year, while the share of children with vaccine exemptions reached an all-time high. The national exemption rate rose to 4.2% during the 2025-2026 school year, up from 3.6% the prior year, representing an estimated 155,000 children.

This marks the fourth consecutive year that the average exemption rate has set a new record. The vast majority of these exemptions are for nonmedical reasons, and increases were seen in 41 states and the District of Columbia.

Health experts attribute the trend to confusion and instability in federal vaccination guidance. U.S. Health Secretary Robert F. Kennedy Jr., who was a prominent vaccine critic before his appointment, has led efforts to revise childhood vaccination recommendations. Earlier this month, President Donald Trump called for a revamp that promotes spacing out childhood shots into separate visits, a theory that has been discredited.

“The root cause of this is primarily because there’s so much chaos and confusion in vaccination recommendation systems in the last year or so,” said Dr. James Campbell, a University of Maryland researcher and chair of the American Academy of Pediatrics’ infectious diseases committee.

The CDC reported that 92.4% of kindergartners received their measles-mumps-rubella shots, down slightly from the previous year. Before the COVID-19 pandemic, the rate was 95%, the threshold considered sufficient to prevent community outbreaks. Rates also fell for polio, the diphtheria-tetanus-pertussis combination shot, and the first chickenpox dose. Hepatitis B vaccination held steady, though experts note it is given at birth and may take years to reflect recent policy changes.

The data comes as the U.S. experiences its worst measles year since 1991. More than a quarter of a million kindergartners are now susceptible to measles, according to Campbell. Unvaccinated children are concentrated in certain areas, explaining why outbreaks vary in intensity.

School and health officials are urging parents to vaccinate their children as the new school year begins. “Back-to-school season is an important reminder that protecting our children’s health is both a shared responsibility and a shared goal,” said Dev Sangvai, North Carolina’s Health and Human Services Secretary.

The CDC has shifted from publishing detailed reports to posting data online with minimal commentary. This year, the agency issued a brief statement acknowledging the decline and encouraging parents to discuss vaccination options with their doctors.

All states require vaccinations for school attendance, but most allow exemptions for religious or other nonmedical reasons. Medical exemptions have remained stable at about 0.2%, while nonmedical exemptions have risen. In Idaho, 17.5% of kindergartners had an exemption, compared to fewer than 0.5% in Connecticut.