The United States has recorded 5,182 confirmed measles cases so far in 2026, according to figures the Centers for Disease Control and Prevention updated on November 6. The total was current through November 5 and had already passed every annual count since 1991. The increase comes as kindergarten measles, mumps and rubella vaccination coverage has slipped below the level public-health agencies say is needed to protect communities. From November 10 to 13, a regional expert commission convened by the Pan American Health Organization will review the elimination status of countries including the United States. The review is a technical assessment, not an automatic penalty for a high case count.

A year-to-date total has crossed a historic threshold

The CDC reported 5,182 confirmed cases as of November 5, compared with 2,289 for all of 2025. The 2026 figure is already about 2.3 times last year's total, even though the calendar year is not finished. The agency's historical series shows 9,643 cases in 1991, followed by 2,126 in 1992 and far lower totals in subsequent years. That makes the current count the highest annual tally since 1991, rather than a new all-time record.

The distinction matters because the headline number is a running total, not a final annual result. CDC says its 2025 and 2026 counts are preliminary and can change as jurisdictions report and confirm cases. The 5,182 figure is therefore a dated snapshot: the number of confirmed cases reported by noon on November 5, published in the agency's November 6 update. It should not be confused with estimates of all infections, which may include probable cases that have not entered the confirmed-case total.

Sources: Measles Cases and Outbreaks · The CDC has recorded more than 5,000 measles cases this year · US measles cases rise to 5,182, CDC says

The outbreak is broad, and most cases are linked to outbreaks

Of the 5,182 cases, 5,164 were reported by 47 US jurisdictions; the remaining 18 involved international visitors to the country. The CDC also recorded 43 new outbreaks during 2026. It classified 4,993 cases, or 96 percent of the national total, as outbreak-associated. Those cases include infections linked to outbreaks that began both this year and in 2025, showing that some transmission chains have continued across calendar years.

That outbreak measure is separate from vaccination status. The CDC's case table also shows that 96 percent of patients were unvaccinated or had an unknown vaccination status; 2 percent had received one MMR dose and 2 percent had received two. The agency counted 562 hospitalizations, equal to 11 percent of reported cases. Adults aged 20 and older accounted for 2,132 cases, while people aged 5 to 19 accounted for 2,104 and children under five for 908. The figures show that the outbreak is not confined to young children.

Sources: Measles Cases and Outbreaks · US measles cases rise to 5,182, CDC says

Pennsylvania has the largest state tally

Pennsylvania remained the hardest-hit state in the latest state-level update. Its Department of Health said on November 6 that 1,487 cases had been confirmed across 45 counties, with 287 hospitalizations and six measles-associated deaths. That was up from 1,467 cases in the department's November 4 update. The state's November 6 release also said five cases had occurred among vaccinated people, less than 1 percent of its total.

The state figure is slightly ahead of the CDC's jurisdiction table, which listed 1,476 Pennsylvania cases in the November 6 page update, based on data current through November 5. The two figures therefore reflect different reporting snapshots: Pennsylvania's release is dated Friday, while the CDC says its national page includes confirmed cases notified by jurisdictions and notes that state health departments may have more current information. The article uses Pennsylvania's latest dated state figure for the state total and the CDC's confirmed count for the national total.

Sources: Measles Cases and Outbreaks · Pennsylvania Department of Health Provides Statewide Update on Measles Outbreak as Cases Reach 1,487 in 45 Counties · US measles cases rise to 5,182, CDC says

Kindergarten vaccination coverage is below the 95 percent benchmark

The CDC reported that MMR coverage among US kindergartners fell to 92.4 percent in the 2025–2026 school year, down from 95.2 percent in 2019–2020. Around 280,000 children attended kindergarten without documentation of completing the MMR vaccine series. The same report found that exemptions from one or more vaccines rose to 4.2 percent, from 3.6 percent a year earlier. These figures describe school-entry coverage, not the vaccination status of every American.

The CDC says that when more than 95 percent of people in a community are vaccinated, most people are protected through community immunity. The national average can hide much lower coverage in particular schools, counties or social networks, where an imported infection can spread among susceptible people. Two MMR doses are about 97 percent effective against measles, compared with 93 percent for one dose. Vaccination does not prevent every breakthrough infection, but it substantially reduces the likelihood of infection and helps limit transmission.

Sources: Measles Cases and Outbreaks · Vaccination Coverage and Exemptions among Kindergartners · Measles Vaccination

PAHO's review will examine transmission evidence, not just case totals

The PAHO Regional Monitoring and Re-Verification Commission is scheduled to meet from November 10 to 13 to review measles, rubella and congenital rubella syndrome across the Americas. In March, PAHO specifically said that the United States and Mexico would have their measles elimination status reviewed at the November annual meeting. For the United States, the assessment period runs from the reported outbreak onset on January 20, 2025, and includes evidence assembled by national health authorities, including viral genome sequencing.

Under PAHO's framework, the key question is whether the same measles virus genotype and lineage has circulated without interruption for 12 months or more within a defined country or area. The commission reviews national reports, epidemiological and laboratory data, molecular evidence and field investigations. It then makes recommendations to the PAHO Director, who formally determines and communicates a country's classification. A large outbreak is serious, but the case count alone does not establish that the technical threshold for re-established endemic transmission has been met.

Sources: Measles and Rubella Elimination Regional Monitoring and Re-Verification Commission to hold sixth annual meeting in November · Update on the review of measles elimination status · Measles and Rubella Elimination Regional Monitoring and Re-Verification Commission

The regional status and the US status are not the same question

The Americas as a region lost its verification as free of endemic measles transmission in November 2025, after PAHO's commission concluded that transmission had been re-established in Canada. That regional decision did not, by itself, determine the separate national status of the United States. PAHO's decision to review the US case reflects the need to assess whether a sustained chain of the same viral lineage has persisted domestically, using evidence that goes beyond the number of confirmed infections.

The CDC's latest figures show why the review matters: the United States has recorded more cases in 2026 than in any year since 1991, while kindergarten MMR coverage remains below the 95 percent benchmark. But the final classification depends on the commission's evidence review and the PAHO Director's formal decision, not on a headline threshold. The national case count is also provisional and will continue to be updated. For now, the confirmed picture is a major resurgence, a widening surveillance burden and a test of whether vaccination, detection and outbreak response can interrupt transmission.

Sources: Update on the review of measles elimination status · Measles and Rubella Elimination Regional Monitoring and Re-Verification Commission · What CDC is Doing About Global Measles · Measles Cases and Outbreaks