US Measles Outbreak 2026: Latest Cases, States, Symptoms and CDC Update
The United States is experiencing significant measles activity in 2026, with thousands of confirmed cases reported across the country. The latest data from the U.S. Centers for Disease Control and Prevention show that measles transmission remains an important public-health issue.
US Measles Cases in 2026
According to the CDC, 3,471 confirmed measles cases were reported in the United States in 2026 as of September 17. Of those, 3,454 cases were reported by 47 jurisdictions, while 17 cases were reported among international visitors to the United States.
The CDC reported 39 measles outbreaks during 2026. Overall, 95% of confirmed cases were associated with outbreaks. The CDC notes that its national figures are based on confirmed cases reported by jurisdictions and that preliminary counts can change.
Which States Have Reported Measles Cases?
The CDC reported confirmed measles cases across 47 jurisdictions. These include:
- Alabama
- Alaska
- Arizona
- California
- Colorado
- Connecticut
- Delaware
- District of Columbia
- Florida
- Georgia
- Idaho
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maine
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Missouri
- Montana
- Nebraska
- New Jersey
- New Mexico
- New York
- North Carolina
- North Dakota
- Ohio
- Oklahoma
- Oregon
- Pennsylvania
- Rhode Island
- South Carolina
- South Dakota
- Tennessee
- Texas
- Utah
- Vermont
- Virginia
- Washington
- West Virginia
- Wisconsin
- Wyoming
Pennsylvania Measles Outbreak
Pennsylvania has reported substantial measles activity during 2026. The Pennsylvania Department of Health reported 792 confirmed cases as of September 21, 2026, according to Reuters.
State-level figures can be updated on a different schedule from the CDC's national dashboard. Readers should therefore check the latest Pennsylvania Department of Health information for local updates.
What Is Measles?
Measles, also known as rubeola, is a highly contagious viral infection. It can spread through the air when an infected person coughs, sneezes or otherwise releases respiratory particles.
People who do not have immunity can become infected after exposure. Measles can cause complications, particularly in young children and other people at higher risk of serious illness.
Common Measles Symptoms
According to the CDC, measles commonly begins with symptoms such as:
- Fever
- Cough
- Runny nose
- Red or watery eyes
- Skin rash
CDC guidance says symptoms can appear approximately 7 to 15 days after exposure. The rash is a key feature of measles illness.
How Does Measles Spread?
Measles is highly contagious. A person who is infected can spread the virus to people who are not immune.
During an outbreak, public-health officials may issue exposure notices and provide recommendations for people who may have been exposed.
MMR Vaccine and Measles Prevention
The CDC identifies the measles, mumps and rubella MMR vaccine as the best way to prevent measles. CDC information states that two doses are about 97% effective against measles.
Children are generally recommended to receive two MMR doses. Vaccination recommendations can differ for adults, international travelers and people who have been exposed during an outbreak.
Anyone with questions about vaccination status should speak with a qualified healthcare professional or local health department.
What to Do If You Have Measles Symptoms
If you develop symptoms that could be measles, particularly after known exposure or travel, contact a healthcare provider before going directly to a medical facility.
Calling ahead allows healthcare facilities to take precautions that can reduce the possibility of exposing other patients and staff.
If you have been exposed to measles, CDC guidance recommends contacting your healthcare provider promptly because vaccination or immune globulin may be considered depending on the circumstances.
Why CDC Numbers Can Change
The CDC explains that its national measles figures are updated using confirmed cases reported by jurisdictions. The national dashboard is updated on a regular schedule, while individual states may publish more current local numbers.
Therefore, the number displayed by a state health department may temporarily differ from the national CDC total.