What Are the Rules on Vaccine Exemptions?

Medically Reviewed by Dan Brennan, MD on May 02, 2023
6 min read

Every state has laws that require children to get certain vaccines before they can go to school or daycare. Yet parents may be able to opt out of one or more vaccines for medical, religious, or personal reasons.

Vaccine exemption laws vary from state to state. Some states make it easier to avoid vaccines than others.

Statistics show that states where exemptions are easy to get have more unvaccinated kids than states that make the process harder. Kids who don't get vaccinated are more likely to get sick. High exemption rates have been linked to outbreaks of diseases like measles, mumps, and pertussis (whooping cough).

The measles outbreaks in 2019 were among the worst in decades with the CDC reporting 1, 274 cases. In 2020, the number of cases of measles in the U.S. declined for the first time in six years. From January 1 to December 31, 2022, a total of 121 measles cases were reported by 6 jurisdictions. In 2022, there were 322  mumps cases. The largest recent outbreak was in 2016 which happened in a close-knit Arkansas community and led to 3,000 cases.

These and other recent disease outbreaks have led some states to consider passing stricter vaccine exemption laws, while others, such as Arizona, have moved to loosen restrictions.

legal vaccination exemptions by state graphic

In 1855, Massachusetts became the first state to require children to get vaccinated to attend school. Other states soon followed with their own vaccination laws. The goal of these laws was to protect children and communities from contagious diseases.

Since then, anti-vaccination groups have challenged vaccine laws. States have had to balance people's rights to personal and religious beliefs with the need to protect public health.

Parents can ask for a medical exemption if a vaccine wouldn't be safe for their child. Reasons that children can get an exemption include:

  • They have a disease or take medicine that weakens their immune system.
  • They have a severe allergy to a vaccine or an ingredient in it.
  • They had a serious reaction to a vaccine in the past.

To get a medical exemption, parents need to have their child's doctor sign a form. Many states ask whether the exemption is temporary or permanent. And almost half of states require doctors to sign a new form every year or so.

This exemption allows parents to opt their child out of vaccines based on their religious beliefs.

Some states ask for evidence that the family belongs to a religious group that objects to vaccines. Only a few religions object to vaccines, including Christian Scientists and some faith healing groups. But in most states with this provision, you can simply sign a form stating that you have religious reasons to opt-out.

This exemption is based on parents' personal beliefs about vaccines. Some parents are concerned about vaccine safety.  Others believe that getting sick is good for the child because it strengthens the immune system. Many of these concerns have been debunked, such as a theory that vaccines cause autism.

All 50 states and the District of Columbia allow medical exemptions. Every state except three -- California, Maine, Mississippi, New York, and West Virginia -- allows religious exemptions. And 15 states let parents decline vaccines for personal reasons.

Personal exemptions are harder to get in some states than in others. In certain states, parents have to do one or more of these things to get a personal exemption:

  • Talk to their doctor or read about the benefits of vaccines and the risks of not vaccinating their children.
  • Get a signature from a local health department official.
  • Write a letter that explains their reasons for refusing vaccines.
  • Renew their exemption form every year.

Medical exemptions prevent kids from getting vaccines that might be unsafe for them. Conditions that weaken the immune system, such as a child with cancer undergoing chemotherapy, and severe vaccine allergies are somewhat rare, so few children need these exemptions.

People who seek personal exemptions say they have a right to decide whether their children should be vaccinated. Vaccine safety is one concern behind exemptions. Some parents fear that the risks of vaccines outweigh the benefits. Most of these worries are based on information they've seen online or in other media, or that they've heard from friends. A commonly cited belief among anti-vaccine groups is that vaccines can cause autism. That belief is based on a 1997 study by a British doctor that was published in the journal The Lancet. The study has since been discredited many times, the doctor lost their medical license, and The Lancet retracted the report. Since then, numerous other studies have found no connection between vaccines and autism.

Vaccines, like all drugs, can in rare cases cause serious side effects. The National Vaccine Injury Compensation Program – which covers most vaccines -- allows people to file a petition if they believe they’ve been hurt by one. According to statistics from the program, from 2006 to 2017, one individual received compensation for every 1 million doses of vaccine given. It has awarded $4.1 billion since 1988. In nearly 80% of cases that received compensation, HHS did not conclude that a vaccine caused the alleged injury.

Vaccines help children avoid serious diseases. High vaccination rates also protect people who can't get vaccinated because they're too young or they have a medical condition that would make vaccines unsafe for them. This is called "herd immunity."

At least 90% to 95% of people in one area need to be vaccinated to protect the whole community against diseases. In one study, a 5% drop in measles, mumps, rubella (MMR) vaccine coverage led to a threefold increase in measles cases each year. This is because even kids who have been vaccinated may be at a small risk if there is a child in the community who has the illness.

"Measles tends to be the disease we see the fastest because it's one of the most highly contagious viruses," says Peter Hotez, MD, PhD, professor of pediatrics and dean of the National School of Tropical Medicine at Baylor College of Medicine in Houston.

Vaccine-preventable diseases like measles can be serious. "Up until a couple of decades ago, measles was the single leading killer of children globally," Hotez says.

Another problem is that exemption laws are hard to enforce. In 2015, California outlawed nonmedical exemptions. After the law passed, medical exemptions jumped 250%. One reason was that some doctors began writing medical exemptions for parents who had personal objections to vaccines.

Overall, vaccination rates in the United States have stayed high. More than 90% of children are vaccinated against measles, mumps, rubella, polio, and chickenpox.

Yet some small communities around the country have high numbers of unvaccinated children. When someone who is sick comes into one of these areas, outbreaks can happen.

One example is measles. The United States wiped out measles in 2000, but people still bring it into the country when they travel to Europe, Israel, or other regions of the world that have outbreaks.

"Typically, the outbreak starts among vaccine refusers," says Daniel Salmon, PhD, professor and director of the Institute for Vaccine Safety at the Johns Hopkins Bloomberg School of Public Health. "Then it spreads to kids who are too young to be vaccinated or who can't get vaccinated for medical reasons. It also spreads to what we call vaccine failures -- kids who have been vaccinated but the vaccine didn't work for them."

States that make it easy to get nonmedical exemptions have more exemptions, and higher rates of vaccine-preventable diseases, than states with tougher laws, research finds. States that offer personal exemptions have more than twice the rate of whooping cough as those that only allow religious exemptions.

If you have concerns about vaccine safety, get advice from a medical professional. "Find a doctor you trust and ask your doctor," Salmon suggests.

You can also learn about vaccines at websites like the CDC and American Academy of Pediatrics, which support vaccination. Some groups may support anti-vaccine views, oppose government-mandated vaccinations or question vaccine safety, such as the National Vaccine Information Center and the Association of American Physicians and Surgeons.

Get informed, but don't wait too long to get your child vaccinated. "These diseases are most serious for young children. If you wait to vaccinate your child, you leave them vulnerable at a time when they're most likely to have complications," Salmon says.

If an adult who was never vaccinated as a child gets one of these diseases, the illness can have serious complications.