The Centers for Disease Control and Prevention reported 4,852 confirmed measles cases in the United States as of October 29, 2026. Three deaths associated with measles were reported in the country during 2026.

Forty-seven jurisdictions reported 4,834 of the confirmed cases. Forty-three new measles outbreaks were recorded, with 4,666 of the total cases (96%) classified as outbreak-associated. A measles outbreak is defined as three or more related cases.

Of the outbreak-associated infections, 3,282 originated from outbreaks that started in 2026, while 1,384 stemmed from outbreaks that began in 2025. Eighteen measles cases were reported among international visitors to the United States in 2026.

During 2025, 45 jurisdictions reported 2,263 cases, and 48 outbreaks were identified. Ninety percent of the 2025 cases were outbreak-associated, and 26 cases involved international visitors.

Why It Matters

Approximately 280,000 kindergartners were at risk during the 2025–2026 school year due to the decreased coverage. Two doses of the MMR vaccine are 97% effective at preventing measles, while one dose is 93% effective. Breakthrough measles infections account for approximately 10% of all measles infections.