Measles Outbreak Tracker: 600+ Cases Across 30 States (April 2026)

2026 Measles Outbreak Update

The United States has confirmed over 600 measles cases across 30 states in 2026 — the largest outbreak in decades. Here’s what you need to know and how to check your state.

Check Your State

Every state’s measles data is available on our measles tracker. Here are the states with the most activity:

States with Confirmed Cases

Visit any state’s page for county-level breakdowns, case timelines, and MMR vaccination data:

Tennessee measles — Our most-viewed measles page
Indiana measles — Active outbreak tracking
Kentucky measles — Cases reported in 2026
Virginia measles — Multiple counties affected
North Carolina measles — Cases near Virginia border

See the full national measles map for all 51 states.

Why Is Measles Coming Back?

The resurgence is linked to declining MMR vaccination rates. Nationally, kindergarten MMR coverage has dropped to 91.5% — well below the 95% threshold needed for herd immunity. 39 states are now below that threshold.

Measles is extremely contagious. One infected person can spread it to 12-18 others in an unvaccinated population. When vaccination rates drop even a few percentage points below 95%, it creates pockets of vulnerability.

Check your state’s vaccination rate on our MMR coverage dashboard.

What You Should Do

Verify your MMR status — Most people need two doses. Check with your doctor if you’re unsure.
Monitor your state — Bookmark your state’s measles page for weekly updates.
Know the symptoms — High fever, cough, runny nose, and a distinctive rash appearing 3-5 days after other symptoms.
Talk to your pediatrician if your children aren’t up to date on vaccinations.

About This Data

Measles case data comes from the Johns Hopkins Measles Tracking project, which compiles reports from state and local health departments. County-level data may be incomplete. The CDC also publishes national case counts, though with different timing.

Updated weekly. Last update: April 3, 2026.