CDC: Measles cases surpass 4,000 in 2026

CDC data show that 96% of cases are outbreak-associated, with adults accounting for 40% of cases, up from 29% in 2025.

By
Teraya Smith
October 12, 2026
3 min

MDSpire News

Overview

The CDC reported 4,080 confirmed US measles cases through October 8, 2026, including 414 hospitalizations and 2 deaths. Most cases were outbreak-associated (96%) and occurred among people who were unvaccinated or whose vaccination status was unknown (95%); kindergarten MMR coverage was 92.4% in the 2025–2026 school year.

Background

The 2026 case total has exceeded the 2,289 confirmed cases reported in 2025. The CDC recorded 42 new outbreaks in 2026, while cases were also linked to outbreaks that began in 2025. National kindergarten MMR coverage declined from 95.2% in 2019–2020 to 92.4% in 2025–2026, with approximately 280,000 kindergartners estimated to be at risk. The CDC notes that local vaccination coverage varies and that surveillance totals are preliminary, exclude probable cases, and may be revised.

Data Highlights

Measure	2026	2025 comparison
Confirmed cases	4,080 through October 8	2,289
Hospitalizations	414 (10% of cases)	244 (11% of cases)
Deaths	2	Not stated in source
Outbreak-associated cases	96% (3,897 cases)	90%
Unvaccinated or vaccination status unknown	95%	93%
Adults aged 20 years and older	40% (1,635); 14% hospitalized	29% (674); 12% hospitalized
Children aged 5–19 years	42% (1,716); 5% hospitalized	Not stated in source
Children younger than 5 years	17% (710); 15% hospitalized	Not stated in source
Kindergarten MMR coverage	92.4% in 2025–2026	95.2% in 2019–2020
MMR vaccine effectiveness	97% after 2 doses; 93% after 1 dose	Not applicable

Key Findings

Of 3,897 outbreak-associated cases in 2026, 2,513 were linked to outbreaks that began in 2026 and 1,384 to outbreaks that began in 2025; the CDC reported 42 new outbreaks in 2026.
Adults aged 20 years and older accounted for 40% of cases in 2026, compared with 29% in 2025. Children aged 5–19 years accounted for 42% and children younger than 5 years for 17% of 2026 cases.
Although hospitalizations rose from 244 in 2025 to 414 in 2026, the proportion of cases resulting in hospitalization decreased from 11% to 10%.
Hospitalization proportions in 2026 were 15% among children younger than 5 years, 14% among adults aged 20 years and older, and 5% among children aged 5–19 years.
The CDC groups people who are unvaccinated with those whose vaccination status is unknown because documentation may be unavailable; the reported 95% should not be interpreted as the proportion confirmed to be unvaccinated.
The CDC reports MMR effectiveness of 97% after 2 doses and 93% after 1 dose; breakthrough infections are uncommon but can occur, particularly in communities experiencing outbreaks.

Clinical Implications

The CDC states that local vaccination coverage can vary considerably, including pockets of unvaccinated individuals in states with high overall coverage. Its reported vaccination-status category combines confirmed unvaccinated people with those whose status is unknown, so it does not quantify confirmed lack of vaccination alone. The CDC’s vaccine guidance states that people without presumptive evidence of immunity should be vaccinated.

Conclusion

Through October 8, 2026, US measles surveillance recorded more confirmed cases and hospitalizations than in 2025, with most cases outbreak-associated. The CDC identifies declining kindergarten MMR coverage and substantial local variation in coverage alongside these provisional surveillance figures.