Are vaccines required by law in the U.S.?

Vaccination requirements in the United States vary by state, but nearly all require certain immunizations for children to attend school. The federal government, through the CDC and FDA, issues recommendations and approves vaccines for safety and efficacy, but enforcement of vaccine requirements happens at the state level. COVID-19 vaccine mandates, flu shot requirements, and updates to the infant vaccine schedule remain politically controversial in some states, including New Hampshire.

What vaccines are required for children?

Each state sets its own immunization schedule for school attendance, but most follow the CDC vaccine schedule for children. This typically includes vaccinations against:

• Measles, mumps, and rubella (MMR)
• Diphtheria, tetanus, and pertussis (DTaP)
• Polio
• Hepatitis B
• Varicella (chickenpox)

These requirements generally apply to children attending public and private K–12 schools and licensed child care facilities. Exemptions are available in every state for medical reasons. Some states also allow religious or philosophical exemptions.

Who decides which vaccines are required?

While the CDC immunization schedule offers national guidance, each state decides whether to adopt, modify, or reject those recommendations. In many states, a Department of Health or similar agency can add new vaccines to the required list by administrative rule. In others, the legislature must approve any additions.

The FDA plays a role earlier in the process by approving vaccines for use based on safety and effectiveness data. This includes both routine childhood vaccines and seasonal shots like the FDA flu vaccines released each fall.

Learn about vaccines required in NH.

Are COVID-19 vaccines required?

No U.S. states currently require COVID19 vaccinations for K–12 school attendance.

In February 2025, a presidential action clarified this further: the executive order “Keeping Education Accessible and Ending COVID19 Vaccine Mandates in Schools” prohibits federal funding from supporting any school—elementary through higher education—that requires COVID19 vaccination as a condition for in-person attendance.

Meanwhile, the CDC continues to recommend COVID19 vaccinations and boosters for some groups.

Are adult vaccines required?

In general, adults are not required by law to receive vaccinations, though some employers (like healthcare providers) may have their own requirements. The CDC recommends flu shots each year, especially for older adults and people with chronic conditions. Other adult vaccines include shingles, pneumococcal, hepatitis A/B, and tetanus boosters.

What changed recently in New Hampshire?

In 2025, New Hampshire made headlines by changing how it handles required immunizations. The state added several vaccines, like varicella and Hepatitis B, directly into state law, rather than relying on rules from the Department of Health and Human Services (DHHS). At the same time, lawmakers removed DHHS’s authority to add new vaccines by rule in the future. That means any future additions, such as updates to the infant vaccine schedule, would require a vote by the Legislature.

Supporters said this increases accountability and transparency. Opponents warned it could slow the state’s response to new health threats.