Kindergarten Vaccine Exemptions Reach a Record 4.2% as Coverage Slips for Every Shot the CDC Tracks

Verified key facts

• Exemptions from routine vaccines among US kindergartners rose to a record 4.2% in the 2025-26 school year, up from 3.6%, covering about 155,000 children, according to CDC data reported by ABC News and CBS News.
• Coverage fell for every vaccine the CDC tracks, ranging from 92.0% for DTaP to 92.4% for MMR and polio, with varicella down from 94% to 93.4%.
• About 280,000 kindergartners attended school without documentation of a completed MMR series, per the CDC data reported by CBS News and Axios.
• Exemptions rose in 41 states and the District of Columbia, and 24 states now report exemption rates above 5%, according to CIDRAP and US News.
• Idaho had the highest exemption rate at 17.5%, followed by Utah, Oregon, Arizona and Nevada, per the CDC figures.
• The CDC measles tracker recorded 2,566 confirmed cases as of 13 August 2026, against 2,289 for the whole of 2025, with 38 outbreaks and 94% of cases outbreak-linked.

A record 4.2%

The share of American kindergartners exempt from one or more routine vaccines has reached 4.2%, the highest figure the Centers for Disease Control and Prevention has recorded. The new data, covering the 2025-26 school year and released this week, puts the number of exempt five-year-olds at roughly 155,000, up from 3.6% the year before.

The rise was reported by ABC News, CBS News and Axios from the CDC's SchoolVaxView collection, which compiles state-level immunisation records for children entering school. The majority of the exemptions were granted for non-medical reasons rather than on clinical grounds.

Every vaccine the CDC tracks moved the wrong way

Exemptions are only half the picture. Coverage itself fell for every vaccine in the collection, which is a different and in some ways more consequential finding, because a child can be unvaccinated without holding a formal exemption at all.

The figures range from 92.0% for the diphtheria, tetanus and acellular pertussis series to 92.4% for both measles, mumps and rubella and polio. Varicella coverage slipped from 94% to 93.4%. None of those declines is dramatic in isolation; the pattern is that all of them moved together and in the same direction.

A uniform decline across unrelated vaccines is diagnostically useful. If one vaccine fell and the others held, the explanation would probably be specific to that product, its supply or a particular controversy attached to it. When every series moves down together, the cause is more likely to sit in the process by which children are enrolled, verified and followed up, or in a general shift in how parents regard the schedule as a whole.

280,000 children without a completed MMR record

The most concrete number in the release concerns measles specifically. Around 280,000 kindergartners attended school during the 2025-26 year without documentation that they had completed the MMR series, according to the CDC data as reported by CBS News.

Documentation is not the same as vaccination, and some proportion of those children will have been immunised without the paperwork reaching the school. But the record is what public health departments act on during an outbreak, and a child whose status cannot be confirmed is treated as susceptible when a case appears in a classroom.

The practical consequence falls on the family rather than on the system. When a case is confirmed in a school, children without documented immunity are generally excluded for the duration of the incubation period, which can run to three weeks. A missing form and a missing vaccination therefore produce the same outcome for the child concerned, whatever the underlying medical reality.

Idaho at 17.5%, and 24 states above five

The national average conceals very wide variation. Exemptions increased in 41 states and the District of Columbia, and 24 states now report rates above 5%, according to CIDRAP and US News. Idaho stands far above the rest at 17.5%, followed by Utah, Oregon, Arizona and Nevada.

An exemption rate approaching one child in six is a different public health situation from a national average of one in twenty-four. Transmission is local, so what determines whether an introduced case becomes an outbreak is the coverage in that classroom, that school and that county, not the figure for the country as a whole.

The clustering is sharper still below state level. Exemptions are not distributed evenly within states; they concentrate in particular districts and particular schools, which means that a state reporting 8% may contain individual classrooms where a third of the children are unvaccinated. Those are the settings in which a single case turns into the outbreaks the CDC has been counting all year.

Why 95% is the number that matters

Epidemiologists use 95% two-dose MMR coverage as the working threshold for interrupting measles transmission in a community. Measles is among the most transmissible diseases known, which is why its threshold sits higher than for almost anything else routinely vaccinated against.

At 92.4% nationally, the United States is below that line in aggregate, and materially below it in the states with the highest exemption rates. Crossing the threshold does not produce an outbreak by itself; it removes the margin that stops a single imported case from becoming one.

Measles in the same year

The coverage data arrives in a year that has already tested it. The CDC's measles tracker recorded 2,566 confirmed cases as of 13 August 2026, exceeding the 2,289 reported across the whole of 2025, with 38 separate outbreaks logged and 94% of confirmed cases linked to one of them.

That linkage figure is the one that connects the two datasets. Sporadic imported cases in a well-covered population produce isolated infections. When 94% of cases belong to outbreaks, the virus is finding clusters of susceptible children and moving through them, which is precisely what falling school coverage would predict.

Idaho, the 95% line and the school year starting now

The data describes a school year that has already finished. The one now beginning is where its consequences land, and the states to watch are the ones where exemption rates are highest and where the summer measles activity reported by local outlets, including in Idaho, has already put health departments on notice.

Two things would change the trajectory. The first is state legislative action on non-medical exemptions, which is where the largest share of the increase sits. The second is catch-up vaccination in the districts furthest below the threshold. Neither happens quickly, and neither is measured again until the CDC publishes the 2026-27 figures a year from now.

Sources

• ABC News - Vaccine exemption rate for kindergarteners reaches record high: CDC
• CBS News - School vaccination rates decline again to record low as exemptions reach new high
• Axios - Kindergarten vaccination rates fell again in 2025-2026, CDC says
• CIDRAP - US kindergarten vaccine exemptions jumped last school year, CDC reports
• US News - Kindergarten Vaccine Exemptions Hit Record High, New CDC Data Show
• Centers for Disease Control and Prevention - SchoolVaxView: Vaccination Coverage and Exemptions among Kindergartners