US Kindergarten Vaccine Exemptions Hit Record High

U.S. kindergarten vaccination rates declined once again during the 2025-2026 school year, while the share of children with exemptions reached an all-time high, according to new CDC data posted Monday. The fraction of kindergartners exempted from vaccine requirements rose to 4.2%, up from 3.6% the year before — approximately 155,000 children nationally.

It is the fourth consecutive year that the national average exemption rate has reached a record, and the vast majority are parents withholding shots for nonmedical reasons. Exemptions increased in 41 states and the District of Columbia, according to AP News.

Vaccination Coverage Slips Across Multiple Diseases

The CDC reported that 92.4% of 2025-26 kindergartners received their required measles-mumps-rubella (MMR) shots, down slightly from the previous year. Before the COVID-19 pandemic, the vaccination rate was 95% — the level that makes it unlikely a single infection will spark a disease cluster or outbreak.

Vaccination rates also fell for polio (92.4%), the combination shot against diphtheria, tetanus and pertussis (92.0%), and the first dose of the vaccine against chickenpox (93.4%). The rate held steady for hepatitis B.

Nonmedical exemptions have risen sharply from 1.9% in 2020-2021 to 4% in 2025-2026, while medical exemptions have remained steady at 0.2%, according to Healio. Twenty-four states now report exemption rates above 5%, up from 17 the year before.

Measles Outbreak Worsens

The vaccination numbers come as the U.S. experiences its worst year for measles since 1991, with 2,566 confirmed cases in 2026 as of mid-August. Nearly all people diagnosed with measles this year — 93% — were unvaccinated. More than 250,000 children entering kindergarten are susceptible to measles, and about 280,000 kindergartners attended school without documentation of completing the MMR vaccine series.

State-level disparities are stark. Idaho had the highest exemption rate at 17.5% of kindergartners, while fewer than 0.5% did in Connecticut. MMR coverage ranged from 98.9% in West Virginia down to 75.2% in Idaho. Only 10 states had coverage above the 95% herd immunity threshold, compared with 19 states during the 2019-2020 school year.

Federal Policy Turmoil Cited as Root Cause

Experts point to turmoil caused by federal health officials as a key driver of the decline. U.S. Health Secretary Robert F. Kennedy Jr., a leading voice in the anti-vaccine movement before President Donald Trump put him in charge of federal health agencies, has repeatedly tried to revise and reduce childhood vaccination guidance.

“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, of the American Academy of Pediatrics.

Earlier this month, President Trump signed an executive order calling for spacing out childhood vaccines and splitting the combined MMR vaccine into three separate single-disease shots. Doctors strongly rejected these recommendations, noting that the current combination vaccine has undergone rigorous safety testing.

“The harm that it will cause is … to induce chaos and confusion into the system, so people aren’t sure what they’re supposed to do,” said Dr. Paul Offit, a Children’s Hospital of Philadelphia vaccine researcher.

Public Health Implications

The Pan American Health Organization is expected to decide in November whether the U.S. still meets measles elimination criteria it has held since 2000. The Americas region as a whole lost its measles elimination status in late 2025 after sustained transmission in Canada.

Dr. Andrew Racine, president of the American Academy of Pediatrics, said the data shows over 92% of kindergarteners are vaccinated, but “anything less than achieving an A+ grade is not good enough.”

“Parents deserve clear, evidence-based guidance about how to protect their children, not competing recommendations issued through political processes,” said Michael Osterholm, a University of Minnesota infectious disease expert. “When families receive conflicting messages, confidence in vaccination suffers, and children ultimately bear the consequences.”

John Grabenstein, a pharmacist and former head of Department of Defense vaccine programs, warned the trend is not slowing. “It’s continuing a long trend in the wrong direction,” he said. “If trends hold, we’ll have twice as many measles cases this year as we did the previous year. It’s just going to keep getting worse.”

What to Watch For

As the school year begins, public health officials are urging parents to ensure their children are up to date on vaccinations. The CDC issued a three-sentence statement noting the small decline and saying it “continues to encourage parents to discuss vaccination options with their doctors.”

The November Pan American Health Organization decision on U.S. measles elimination status will be a critical milestone. If trends continue, experts warn, the nation could face even larger outbreaks in the coming years.