The standard measles vaccine schedule

Children in the United States receive the measles vaccine as part of the MMR vaccine (measles, mumps, rubella), given in two doses. The first dose is administered at 12 to 15 months of age. The second dose comes at 4 to 6 years old, typically before school entry.

This two-dose schedule protects roughly 97 percent of children who receive both shots. The spacing between doses matters: the second dose should come at least 28 days after the first. If a child receives both doses on the same day, that still counts as the full series.

Some children may need the vaccine on a different timeline. Infants traveling internationally can receive an early dose at 6 to 11 months old, though this dose does not count toward the two-dose series—they still need the standard two doses later. Healthcare providers may also recommend earlier vaccination for children in high-risk situations, such as during an outbreak.

Key Takeaways

  • The first MMR dose is given at 12 to 15 months, and the second at 4 to 6 years old.
  • Both doses are necessary for full protection; one dose alone leaves children vulnerable to measles.
  • Children traveling internationally before age one can receive an early dose, but still need the standard two-dose series later.
  • If your child missed the scheduled doses, catch-up vaccination can happen at any age with at least 28 days between doses.
  • Your pediatrician or local health department can tell you whether your child is up to date based on their age and vaccination record.

Why the vaccine is given at these specific ages

The 12-to-15-month timing for the first dose balances two competing factors. Maternal antibodies—protection passed from mother to baby through the placenta—fade during the first year of life. If the vaccine is given too early, those lingering antibodies can interfere with the vaccine's effectiveness. By 12 months, most maternal protection has waned enough that the vaccine will work.

The second dose at 4 to 6 years old catches the small percentage of children whose immune systems did not respond fully to the first dose. This second shot ensures that nearly all vaccinated children develop lasting immunity before school age, when measles spreads more easily among groups of unvaccinated or under-vaccinated children.

What happens if your child missed the scheduled doses

Children who miss their scheduled MMR doses can receive the vaccine at any point afterward. There is no need to restart the series if a dose was delayed—the next dose simply continues from where the schedule left off. The only requirement is that the two doses are separated by at least 28 days.

If your child is school-age and has not yet received any MMR vaccine, both doses can be given with 28 days between them, rather than waiting years. Many schools require proof of MMR vaccination for enrollment, so catching up before school entry avoids delays or exclusion during outbreaks.

Measles vaccine and other vaccines on the same day

The MMR vaccine can be given on the same day as other vaccines without reducing effectiveness of either. Common vaccines given alongside MMR include the varicella (chickenpox) vaccine, polio vaccine, and others on the standard childhood schedule.

If your child receives MMR and varicella on the same day, they count as separate vaccinations. If they are given on different days, there must be at least 28 days between them. Your pediatrician's office tracks these details and will schedule accordingly.

Who should not receive the MMR vaccine

Most children can safely receive the MMR vaccine. However, certain conditions warrant a conversation with your pediatrician before vaccination. Children with severe allergies to gelatin or the antibiotic neomycin should not receive MMR. Infants under 12 months old should not receive the vaccine (except in rare outbreak situations), because their immune systems are not yet ready to respond.

Children with weakened immune systems—from certain medications, HIV, or other conditions—may not be able to receive the live MMR vaccine. In these cases, your pediatrician may recommend waiting until immunity improves, or may determine that the benefits of vaccination outweigh the risks. This is a decision made on a case-by-case basis with your child's medical team.

Pregnancy is not a reason to vaccinate, but it is a reason not to vaccinate: the MMR vaccine should not be given to pregnant people or those planning pregnancy within the next month. If a woman of childbearing age needs the vaccine and is not pregnant, she should use contraception for 28 days after vaccination.

How to know if your child is up to date

Your child's vaccination record—either a paper card from your pediatrician or a digital record in your state's immunization registry—shows which doses have been given and when. Schools and childcare centers often ask to see this record during enrollment.

If you cannot find your child's record, your pediatrician's office can look it up in their system or contact your state health department's immunization registry. Some states allow you to check your own records online through the state health department website. If doses are missing, your pediatrician can give you a plan for catch-up vaccination.

Frequently Asked Questions

Can my child get measles even if vaccinated?

Measles is extremely rare in fully vaccinated children. The two-dose MMR series is about 97 percent effective. The small number of vaccinated people who do get measles typically have milder illness with fewer complications than unvaccinated people.

Is the MMR vaccine safe?

The MMR vaccine has been used for decades and monitored continuously for safety. Common side effects are mild: arm soreness, low fever, or a rash a week or two after vaccination. Serious side effects are extremely rare. Your pediatrician can discuss what to expect after vaccination.

What if my child was vaccinated but I lost the record?

Contact your pediatrician's office with your child's date of birth. They can search their records or request information from previous providers. If no record exists, your child can receive the MMR vaccine again—getting an extra dose is safe and does not cause problems.

Does my child need a booster dose after age six?

No. Two doses of MMR vaccine provide lifelong immunity for the vast majority of people. A third dose is not part of the standard schedule. If your child has a weakened immune system, your doctor may recommend additional doses.

Can adults get the MMR vaccine if they were never vaccinated as children?

Yes. Adults born in 1957 or later who have no record of MMR vaccination can receive the vaccine. Two doses, 28 days apart, provide the same protection as in children. Your doctor can assess whether you need the vaccine based on your age, vaccination history, and measles immunity.