Vaccine exemptions among U.S. kindergarteners rose to 4.2 percent in the 2025-2026 school year, the highest rate on record, according to new data from the Centers for Disease Control and Prevention. The figure climbed from 3.6 percent the prior school year, a 0.6-percentage-point jump that translates to roughly 155,000 kindergarteners holding exemptions from at least one required vaccine.
The increase was not regional. Exemption rates rose in 41 states and Washington, D.C. and nearly half of all states now report exemption rates above 5 percent. Public health officials mark 5 percent as a threshold above which clusters of under-vaccinated children form, increasing the risk that outbreaks take hold and spread.
Vaccination coverage fell across every childhood vaccine the CDC tracks nationally. National coverage ran from 92.0 percent for DTaP—the diphtheria, tetanus and whooping cough vaccine—to 92.4 percent for MMR and polio. Both figures sit below the 95 percent threshold that epidemiologists cite as necessary to limit measles transmission in a community. Coverage for MMR, DTaP, polio and varicella declined in more than half of states.
Overall kindergarten vaccination coverage dropped about 0.1 percentage point from the previous school year. Applied across a national kindergarten cohort, that removes tens of thousands of children from herd protection for diseases that spread person to person.
The data expose a gap beyond formal exemptions. About 280,000 kindergarteners attended school without documentation showing they had completed the MMR vaccine series. That group is separate from and in addition to those who hold formal exemptions—meaning the true number of under-protected kindergarteners is larger than the exemption count alone suggests.
The numbers land in a specific political context. President Trump signed an executive order on Aug. 10, 2026, calling for childhood vaccine shots to be spaced out into separate visits rather than given on the combined schedules currently recommended by the CDC and the American Academy of Pediatrics. The order represents a formal policy departure from the standard immunization schedule that has governed pediatric care for decades.
Trump has also directed Health and Human Services Secretary Robert F. Kennedy Jr. to pursue further research on vaccines. Kennedy, who built a public profile over years of skepticism toward vaccine safety and the federal vaccination schedule, now oversees the department that includes the CDC, which publishes the immunization data showing coverage declining.
The CDC data do not establish a causal link between any specific policy or official's statements and the rise in exemptions. The exemption rate has climbed steadily over several school years, predating the current administration. But the 2025-2026 figures represent the steepest single-year jump in recent data, and they arrive as the federal government's posture toward routine vaccination has shifted.
Who grants exemptions varies by state. Most states allow medical exemptions; a growing number permit religious or philosophical exemptions with few or no required steps. States with loose exemption laws consistently show higher non-vaccination rates, and the CDC data show the exemption increase was broad enough to cover states across different legal regimes.
The measles benchmark is the most-cited public health marker in this debate. The disease requires roughly 95 percent population immunity to stop transmission chains. National MMR coverage at 92.4 percent means the country as a whole is below that threshold, and individual communities with higher exemption concentrations fall further still. The United States recorded measles outbreaks in recent years tied directly to clusters of unvaccinated children in schools and daycare centers.
The CDC data do not include a breakdown by exemption type—medical versus religious versus philosophical—at the national level in the figures cited. That breakdown matters for policy because medical exemptions are generally small in number and stable; the growth in overall exemptions largely reflects the expansion of non-medical categories.
For the 2025-2026 school year, the record 4.2 percent exemption rate and the 280,000 children attending without MMR documentation together define the scope of the coverage gap the country is carrying into the next respiratory virus season.
