At noon on June 18, 2026, the Centers for Disease Control and Prevention updated its official measles tracker with a figure that represents a public health milestone few anticipated reaching: 2,104 confirmed measles cases reported in the United States in 2026 alone. The cases span 41 jurisdictions — Alaska, Arizona, California, Colorado, Connecticut, the District of Columbia, Florida, Georgia, Idaho, Illinois, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Montana, Nebraska, New Jersey, New Mexico, New York City, New York State, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Texas, Utah, Vermont, Virginia, Washington, Wisconsin, and Wyoming — plus 11 additional cases in international visitors.
There are 30 active outbreaks in 2026, with 93% of cases — 1,957 of 2,104 — classified as outbreak-associated. Of those, 613 are linked to outbreaks that began in 2026; the remaining 1,344 trace back to outbreaks that started in 2025 and have continued without interruption.
The Pan American Health Organization (PAHO) is scheduled to formally assess the U.S. measles elimination status in November 2026. Elimination requires no endemic domestic transmission for 12 consecutive months. Public health experts and CIDRAP tracking widely anticipate that the assessment will confirm the U.S. has lost the elimination status it has held since 2000 — a 26-year achievement that served as one of the signature successes of American public health.
Three deaths have been confirmed since the combined 2025–2026 outbreak began: two unvaccinated children in Texas and one unvaccinated adult in New Mexico. These were the first measles deaths in the United States since 2015.
The Vaccination Data Behind the Outbreak
The numbers make the driver of the outbreak unmistakable. According to the CDC's June 18 data, approximately 92% of confirmed 2026 cases involved people who were unvaccinated or had unknown vaccination status. The MMR vaccine provides 93% protection after one dose and 97% after two, making high vaccination coverage the decisive variable in whether outbreaks spread or are contained.
Herd immunity against measles requires approximately 95% of the population to be vaccinated. Below that threshold, even small pockets of unvaccinated individuals in schools, religious communities, or close-knit social networks can sustain active transmission. U.S. News tracking has documented that a 1% decline in childhood MMR vaccination rates could, according to a Common Health Coalition report, cause 17,000 additional measles cases, 4,000 hospitalizations, and 36 preventable deaths annually.
The largest single outbreak since measles was declared eliminated — the 2025–2026 South Carolina outbreak — reached 997 total cases concentrated in Spartanburg County, which was declared the "ground zero" of the epidemic. The Utah outbreak, which has become the current center of active transmission after the South Carolina outbreak was officially declared over, has spread to 22 of the state's 29 counties. Utah's school vaccination rate in 2024–2025 was 88.6%, well below the 95% herd immunity threshold. The state legislature is currently considering proposals that would further ease MMR exemption requirements.
| Metric | 2026 Data |
| Confirmed cases (as of June 18) | 2,104 |
| Jurisdictions affected | 41 |
| Active outbreaks | 30 |
| Outbreak-associated cases | 93% (1,957 of 2,104) |
| Unvaccinated or unknown vaccination status | ~92% of cases |
| Confirmed deaths (2025–2026 combined) | 3 |
| Hospitalization rate | ~6% |
| U.S. elimination status held since | 2000 |
Who Is Most at Risk and What Parents Need to Know
Measles is among the most contagious infectious diseases known. The CDC states that if one infected person enters a room, up to nine out of ten unprotected people nearby will contract the virus. The virus remains viable in the air for up to two hours after an infected person has left. Unvaccinated individuals who are exposed to measles have approximately a 90% probability of becoming infected.
Age distribution in the current outbreak spans a wide range. Johns Hopkins Bloomberg School of Public Health analysis found that roughly a quarter of 2025–2026 cases were in children under age 5, approximately half were in school-aged children 5 to 19, and a quarter to a third were in adults over 20. This distribution reflects both the concentration of unvaccinated children in school settings and a growing pool of unvaccinated or under-vaccinated adults who missed doses during the COVID-19 disruption period.
Measles symptoms begin 10 to 14 days after exposure and typically start with high fever, cough, runny nose, and red, watery eyes, followed three to five days later by the characteristic rash beginning at the hairline and spreading downward. Complications can include pneumonia, brain swelling, and, in rare cases, death. Children under 5 and adults over 20 face the highest risk of severe complications. Six percent of 2026 cases required hospitalization, mostly children under 19.
The CDC warned state and local health departments in recent weeks that "additional measles cases are anticipated in the coming months" due to increased summer travel and large gatherings. Parents should verify their children's MMR vaccination status immediately, particularly before any travel to states currently reporting active outbreaks or any international travel.
A Preventable Crisis — and the Questions It Raises
The scale and trajectory of the 2025–2026 measles resurgence raises a direct question that public health officials have not yet answered with a formal policy shift: if 92% of cases involve unvaccinated or vaccination-status-unknown individuals, and the MMR vaccine is 97% effective after two doses, why is vaccination coverage below the herd immunity threshold in so many U.S. communities?
ASTHO analysis identifies rising vaccine hesitancy, misinformation, and gaps in access as the primary drivers. The CDC's recent changes to its childhood vaccination guidance — which moved several vaccines to a "shared clinical decision-making" model requiring individual parental consultation before administration — have drawn criticism from pediatricians who say the changes create confusion and risk further depressing MMR uptake. Experts cited in Healthline reporting noted that "conflicting recommendations from national organizations and states now create confusion with parents and guardians and ultimately may cause increased vaccine declination."
The U.S. has beaten back measles before. In 2019, the country came close to losing elimination status with nearly 1,300 cases, primarily in New York. An aggressive public health campaign, including mandatory vaccination orders in affected New York communities, brought that outbreak under control within months. The 2025–2026 outbreak is significantly larger and more geographically dispersed, making a similar localized containment response more difficult to execute at scale.
Frequently Asked Questions
How many measles cases have been confirmed in the U.S. in 2026?
As of CDC's June 18, 2026 noon update, 2,104 confirmed measles cases have been reported in 41 jurisdictions, with 30 active outbreaks. Ninety-three percent of cases are outbreak-associated.
Is the U.S. about to lose measles elimination status?
Yes, according to public health experts and CIDRAP tracking. The Pan American Health Organization is scheduled to formally assess U.S. status in November 2026. Elimination requires no endemic domestic transmission for 12 consecutive months — a bar the current outbreak makes virtually impossible to meet.
What is the risk of getting measles if unvaccinated?
The CDC states that up to 9 out of 10 unprotected people near an infected person will contract measles. The virus can linger in the air for up to two hours after an infected person has left a room.
Who is dying from measles in 2026?
Three deaths have been confirmed since the combined 2025–2026 outbreak began — two unvaccinated children in Texas and one unvaccinated adult in New Mexico. All three were unvaccinated. These are the first measles deaths in the U.S. since 2015.
How can families protect themselves right now?
Verify that all family members have received two MMR doses. Children should receive the first dose at 12–15 months and the second at 4–6 years. Adults born after 1957 who cannot verify vaccination should consult their physician about receiving the MMR vaccine. Contact your pediatrician or local health department if you have questions about your child's vaccination status.
