The vaccination rates for U.S. kindergarteners dropped slightly last year, while exemptions rose to new heights, according to federal data. The exemption rate climbed to 4.2%, increasing from the previous year’s 3.6%. This change affects an estimated 155,000 children nationwide during the 2025-2026 school year. It’s the fourth year in a row that the exemption rate has set a record, with most parents opting out of vaccinations for nonmedical reasons. The increase in exemptions was noted in 41 states and the District of Columbia.
Experts link this trend to upheaval initiated by federal health officials. Previously involved in the antivaccine movement, U.S. Health Secretary Robert F. Kennedy Jr. had a notable role before his appointment by President Donald Trump. Over the past 18 months, Kennedy and federal officials have pushed to adjust and reduce vaccination guidance for children. Earlier this month, Trump suggested changes in childhood vaccination guidelines that support his unfounded theory about spreading vaccinations over several doctor visits.
“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,” explained Dr. James Campbell from the American Academy of Pediatrics.
Several vaccination rates saw declines. The CDC reported that only 92.4% of 2025-26 kindergarteners received mandatory measles-mumps-rubella shots, slightly down from the previous year. Pre-COVID-19 pandemic rates were at 95%, a threshold preventing disease cluster outbreaks from a single infection. Rates also decreased for polio, the combination vaccine protecting against diphtheria, tetanus, and pertussis, and the initial chickenpox vaccine dose. However, hepatitis B vaccine rates remained stable. This vaccine is given shortly after birth, so recent federal policy shifts might not immediately impact kindergarten vaccination rates as highlighted by Campbell.
The CDC data comes amidst the worst measles outbreak in the U.S. since 1991. More than a quarter million children entering kindergarten are at risk for measles, according to Campbell, a researcher at the University of Maryland who leads the AAP’s infectious diseases committee. Unvaccinated children aren’t equally distributed throughout the country, causing varying measles outbreak intensity in different regions.
School and health officials across the nation are reminding parents of vaccination’s importance as schools resume.
“Back-to-school season is an important reminder that protecting our children’s health is a shared responsibility and goal,” stated North Carolina Health and Human Services Secretary Dev Sangvai. “Vaccines help keep our children and teens healthy and in the classroom.”
Historically, the CDC published vaccination coverage data in the Morbidity and Mortality Weekly Report, accompanied by commentary on trends and vaccine importance. Since the Trump administration began, the data has been posted online with minimal narrative. This year’s release offered a brief statement acknowledging the slight decline in vaccination coverage and advised parents to consult with doctors about vaccination options.
Though medical exemption rates remain constant, the increased exemptions for nonmedical reasons are concerning. Schools often serve as centers for germ spread and community outbreaks, making kindergarten vaccination rates crucial. The majority of U.S. states and territories mandate specific vaccines for school attendance, including immunizations against measles, mumps, polio, tetanus, whooping cough, and chickenpox. While medical exemptions remain at about 0.2%, nonmedical exemptions are rising. Recent data shows 17.5% of kindergarteners in Idaho had an exemption for at least one vaccine, compared to less than 0.5% in Connecticut.
Support for the Associated Press Health and Science Department comes from the Howard Hughes Medical Institute’s Department of Science Education and the Robert Wood Johnson Foundation. The AP is solely responsible for the content.