The number of parents in the U.S. choosing not to vaccinate their children rose dramatically in the last school year, according to data released Monday by the Centers for Disease Control and Prevention.

All states require certain vaccines for children entering public school. During the 2025-26 school year, 4.2% of kindergartners, about 155,000 kids, had at least one vaccine exemption, up from 3.6% the previous school year. The vast majority of those exemptions were labeled as “non-medical,” meaning that parents or caregivers were opting out of the shots for personal or religious, rather than health, reasons. Medical exemptions remained stable at 0.2%.

Last week, President Donald Trump signed an executive order to drive down the number of vaccines recommended for kids, a move that drew widespread criticism from pediatricians and public health advocates.

However, the new data reflects a trend of families resisting school vaccine requirements that began during the height of the Covid pandemic.

Forty-one states and Washington, D.C., reported increases in exemptions, according to the CDC.

The rise is “disappointing, but not surprising,” said Dr. David Margolius, director of the Cleveland Department of Public Health. “It’s indicative of the lack of clear messaging at the national level about vaccines.” Ohio’s vaccine exemption rate was at 5.7%, according to the CDC data, up from 4.7% the year before.

Routine vaccination coverage for kindergartners dropped to 92% for the shot that protects against diphtheria, tetanus and whooping cough (DTaP), and 92.4% for the measles-mumps-rubella (MMR) vaccines.

That’s far lower than the 95% of the community that medical experts say need to be vaccinated against measles to prevent outbreaks.

This year marked a 35-year high in the nation’s number of measles cases. As of Monday, the country had logged 2,566 cases in 2026 alone, with ongoing outbreaks in several states, including Ohio, Pennsylvania and Utah.

The continued spread threatens the nation’s status of having eliminated measles from circulation achieved in 2000. The Pan American Health Organization is expected to make a decision on that in November.

Two doses of the MMR vaccine offer 97% protection against measles, usually for life. The number of kindergartners without a record of having both of those shots before school was about 280,000 last year, the CDC said.

Nearly all people diagnosed with measles this year, 93%, were unvaccinated.

In a statement to the media, the CDC said it “continues to encourage parents to discuss vaccination options with their doctors.”