Measles in 2026: Which States Have Cases and What You Should Know

Measles Cases Are Rising in 2026

The United States has seen a significant increase in measles cases in 2026 compared to recent years. As of this week, over 600 confirmed cases have been reported across 30 states — already surpassing the total for all of 2025.

This article breaks down where cases are occurring, why outbreaks keep happening, and what it means for your family.

Where Are Measles Cases in 2026?

Measles outbreaks in 2026 have been concentrated in states with pockets of low MMR vaccination coverage. You can check your state’s current case count on our measles tracker.

Several states have reported active outbreaks this year, with case counts ranging from single digits to dozens. The pattern consistently shows that communities with vaccination rates below 95% are most vulnerable to sustained transmission.

Why Are Outbreaks Happening?

Three factors are driving the increase:

Declining vaccination rates — The national kindergarten MMR coverage rate has dropped to 91.5%, well below the 95% threshold needed for herd immunity. See state-by-state MMR rates.
International travel — Most measles introductions into the US come from travelers returning from countries with active outbreaks. One infected traveler can spark a local outbreak in an under-vaccinated community.
Waning awareness — Because measles was effectively eliminated in the US in 2000, many parents have never seen the disease and may underestimate its seriousness.

How Contagious Is Measles?

Measles is one of the most contagious diseases known. A single infected person can spread it to 12-18 others in an unvaccinated population. The virus can linger in the air for up to two hours after an infected person has left a room.

For comparison, the flu spreads to about 1-2 people per infected person, and COVID-19 (original strain) spread to about 2-3.

What Should You Do?

Check your vaccination status. Most people born after 1957 should have received two doses of MMR vaccine. If you’re unsure, your doctor can check your immunity with a blood test.
Check your state’s coverage rate. Our MMR coverage map shows whether your state meets the 95% herd immunity threshold.
Stay informed. We update our measles case tracker weekly with the latest confirmed case counts from every state.

How We Track This Data

Local Health Signal pulls measles case data from the Johns Hopkins Measles Tracking project and processes it into state-by-state summaries. MMR coverage data comes from the CDC’s SchoolVaxView survey of kindergarten vaccination rates. Both are described in detail on our data sources page.

This article is updated weekly as new data becomes available. Last update: March 25, 2026.