The Centers for Disease Control and Prevention has reported 5,182 confirmed measles cases in the United States so far in 2026, the highest annual total since 1991.1,3,4
The total, confirmed in updated federal data, includes cases in 45 states and Washington, D.C., and 18 cases among international visitors. It is more than double the 2,289 confirmed cases reported in 2025 and puts the country's elimination status up for reassessment this month.1,3,4
Children and teenagers account for about 59 percent of confirmed cases. Children below age five make up 18 percent of cases, while children between ages five and 19 account for 41 percent, and a plurality of cases has been recorded among those aged five to 19. The CDC said 4,993 cases were outbreak-associated.1,4
About 96 percent of cases are among people who are unvaccinated or whose vaccination status is unknown, according to the CDC. Two percent of cases are among people who received one dose of the measles, mumps, rubella vaccine and 2 percent are among people who received the recommended two doses. At least 11 percent of cases have resulted in hospitalization, including more than 1 in 10 children under five years old.4
The CDC recommends two doses of the MMR vaccine, the first at 12 to 15 months and the second between 4 and 6 years old before school entry. The agency says one dose is 93 percent effective and two doses are 97 percent effective against measles. Vaccination coverage among kindergarteners decreased from 95.2 percent during the 2019-2020 school year to 92.4 percent in the 2025-2026 school year.4,1
The number of deaths is not yet fully agreed. The CDC has confirmed four of the deaths so far but said the number is "subject to change." State health officials have confirmed eight measles-associated deaths in 2026: six in Pennsylvania, one in New York and one in Wisconsin.4,1,3
Three of those state confirmations came this week. On Wednesday, the New York State Department of Health reported a measles-associated death of a child who lived in upstate New York, the first known such death in the state in more than 30 years. Another death was confirmed Wednesday in Pennsylvania among an unvaccinated resident of Jefferson County in the northwestern part of the state. On Thursday, Wisconsin health officials said an infant died with measles, the first death in the state since 1990.4
Pennsylvania, the state hardest hit by the outbreak, has reported 1,487 cases this year. The federal death count has been at the center of a dispute between Pennsylvania Gov. Josh Shapiro and Health Secretary Robert F. Kennedy Jr. over how measles deaths are classified. Pennsylvania reports "measles-associated" deaths when a person with confirmed measles dies within 30 days of developing symptoms, unless the death resulted from an unrelated event.1
In August, Pennsylvania reported that two unvaccinated people died of measles. The CDC initially included the deaths in its national tally but subsequently removed them after Kennedy questioned whether measles had caused or contributed to the fatalities. The CDC has said it is working with the U.S. Council of State and Territorial Epidemiologists to establish a standardized definition for measles deaths.1
Infectious disease experts warn that the dispute puts the CDC at odds with a longstanding approach to tracking the consequences of measles. Epidemiologists have said tracking "measles-associated" deaths has long been a standard used by the World Health Organization and the CDC. Kennedy has said his agency was focused on finding treatments for unvaccinated individuals and issued guidance that the illness can be treated by simple vitamins, while saying the vaccine had not been "safety tested" and was not effective for long-term prevention.1,3
The United States declared measles eliminated more than two decades ago, in 2000, after long-term use of the vaccine reduced risk and exposure. If a single viral strain is found to have circulated in the country for 12 months, the U.S. will no longer qualify for that status. Measles cases have also increased globally, particularly in communities that are vaccine-sceptical or where there are gaps in health care access, and experts warn that declining vaccination rates in one geographic location can leave people thousands of miles away vulnerable.1,3
The elimination status is up for reassessment this month, and the CDC has said its death count is "subject to change."3,4
