The rate of exemptions from routine childhood vaccines among US kindergartners reached a record high of 4.2% during the 2025-26 school year, according to new data released by the Centers for Disease Control and Prevention (CDC) on Monday. This marks an increase from 3.6% in the previous school year and 2.2% during the 2020-21 school year.
CDC data indicates that the majority of these exemptions were for non-medical reasons. Concurrently, the percentage of kindergartners who received the measles, mumps, rubella (MMR) vaccine slightly decreased to 92.4%. This figure falls below the 95% rate observed before the pandemic, which medical professionals consider necessary for maintaining herd immunity. The 2025-26 school year has also seen a record number of measles cases.
Vaccination rates for the varicella, or chickenpox, vaccine also saw a decline, moving from 94% to 93.4% during the 2025-26 school year. However, the rate for two doses of the varicella vaccine slightly increased from 92.1% to 92.2%. Rates for the DTaP (diphtheria, tetanus, and pertussis) vaccine, also known as DTP or DT, experienced a slight dip from 92.1% in the 2024-25 school year to 92% in the 2025-26 school year. Hepatitis B vaccination rates remained consistent with the previous school year.
Dr. David Margolius, director of the Cleveland Department of Public Health and chair-elect of the Big Cities Health Coalition, expressed concern over the trend, noting that childhood vaccination rates have been declining for some time. He suggested that the increase in exemptions could be attributed to both growing parental opposition to routine childhood vaccines and barriers that make it difficult for parents to vaccinate their children. Dr. Margolius believes both factors are at play, observing that many individuals were separated from their usual healthcare providers during and after the COVID-19 pandemic.
The data revealed that Idaho had the highest overall exemption rate, including both medical and non-medical exemptions, at 17.5% during the 2025-26 school year. Idaho was followed by Utah, Oregon, Arizona, and Nevada. Conversely, California, New York, and West Virginia recorded the lowest exemption rates at 0.1% each, with Connecticut and Maine also having low rates.
