Important: VAERS reports alone cannot determine if a vaccine caused an adverse event. Reports may contain incomplete, inaccurate, or unverified information. Correlation does not equal causation.
In the United States, vaccine requirements for school are set state by state — not by the federal government. This guide explains how the system works in 2026: which vaccines are commonly required, the three types of exemptions, and how state laws have shifted in recent years.
Understanding state vaccine requirements is important for parents enrolling children in school, families moving between states, healthcare providers counseling patients, and anyone trying to understand why vaccination coverage — and VAERS reporting patterns — vary geographically. Requirements shape behavior, and behavior shapes the data.
Every state and the District of Columbia require certain vaccinations for children to attend public school and licensed childcare. These laws exist to maintain high community immunity and prevent outbreaks of diseases like measles and pertussis in settings where children gather. While the CDC publishes a recommended national immunization schedule, it is each state legislature and health department that decides which of those vaccines are legally mandatory for enrollment — and what exemptions are available.
The result is real variation. A vaccine required in one state may be only recommended in a neighboring one, and the ease of obtaining an exemption differs dramatically across state lines.
Although the exact list varies, most states require documented protection against the following before kindergarten entry:
Younger children in daycare are often also required to have Hib and pneumococcal (PCV) vaccines. Adolescents entering middle school frequently must show a Tdap booster and, in many states, meningococcal (MenACWY) vaccination. HPV vaccination is mandated for school entry in only a handful of jurisdictions.
States allow families to opt out of some or all requirements through exemptions, which fall into three categories:
Over the past decade, several states removed non-medical exemptions, usually in response to outbreaks. California eliminated both religious and philosophical exemptions after a 2014–2015 measles outbreak linked to Disneyland. New York removed its religious exemption in 2019 during a large measles outbreak. Maine and Connecticut also ended non-medical exemptions in recent years. These states — along with Mississippi and West Virginia, which have long allowed only medical exemptions — now have the strictest school-entry laws in the country and correspondingly high vaccination coverage.
Movement has not been in one direction. Some states have made exemptions easier to obtain or have expanded personal-belief options, and legislative proposals to broaden exemption access appear regularly. Because the legal landscape shifts each session, families should always verify the current rules rather than rely on prior years. The variation in exemption policy is one factor behind differences in reported vaccine coverage — and, indirectly, in the volume of adverse event reports — from state to state.
States with stricter requirements tend to have higher childhood vaccination coverage, while states with easy philosophical exemptions often see lower coverage and larger pockets of susceptibility. VaccineWatch lets you explore VAERS adverse event reports by state to see how reporting patterns differ geographically. Keep in mind that report counts reflect population size, vaccination volume, and local reporting practices — not necessarily differences in vaccine safety. Our geographic patterns analysis explores these nuances, and the reporting bias article explains why raw counts require careful interpretation.
In addition to K–12 requirements, many colleges and universities mandate additional vaccines for incoming students, including:
College requirements are typically set by the institution (not the state), meaning students attending private universities in states with broad exemptions may still face strict vaccine requirements.
Rising exemption rates in some states have contributed to localized outbreaks of vaccine-preventable diseases. Measles outbreaks in 2019 and pertussis clusters in subsequent years have been concentrated in areas with high non-medical exemption rates. Public health experts track exemption rates as a leading indicator of community vulnerability, and several states have responded by tightening exemption procedures — for example, requiring physician counseling before granting a philosophical exemption.
The tension between parental autonomy and community disease prevention remains one of the most debated areas of vaccine policy. VaccineWatch presents the data without taking a position on these policy questions.
Requirements are published by each state's department of health and by individual school districts, and they are updated periodically. Before enrolling a child, check your state health department's website for the current required vaccines, accepted forms of documentation, and the exemption process. For questions about which vaccines your child needs and when, consult the CDC vaccine schedule and your pediatrician. General questions about how this site's data works are answered in our FAQ.