The United States has witnessed a dramatic spike in measles cases, with over 5,000 reported in 2026, marking the highest number since 1991.

In a significant public health development, the United States has recorded more than 5,000 cases of measles in 2026, surpassing the previous high set in 1991 12. This latest surge in measles cases underscores a growing concern for public health officials.
The CDC has confirmed that 5,182 cases of measles were officially documented this year, a stark contrast to the 2,289 cases reported in 2025 12. Among these cases, nearly 5,000 have been linked to outbreaks, highlighting the contagious nature of the disease 2.
Demographically, the impact of measles has been notably felt by younger Americans. Children under five years old account for 18% of the cases, while those aged five to nineteen make up 41% of the total 2. Together, children and teenagers represent approximately 59% of all confirmed cases, emphasizing the importance of vaccination in these age groups 2.
A concerning trend is the drop in vaccination coverage among US kindergarteners, which fell from 95.2% in 2019-2020 to 92.4% in 2025-2026 2. This decline in immunizations likely contributes to the increased number of measles cases observed recently 2.
Pennsylvania stands out as one of the hardest-hit states, with six deaths and 1,487 cases reported this year 2. However, there is a disagreement between Pennsylvania Governor Josh Shapiro and US Health Secretary Robert F Kennedy Jr regarding the classification of measles-related deaths 2. According to Pennsylvania’s criteria, a death is considered measles-associated if it occurs within 30 days of symptom onset, unless the cause is unrelated 2.
Two unvaccinated individuals in Pennsylvania lost their lives to measles in August, but these fatalities were later excluded from the CDC’s national count 2. To address this discrepancy, the CDC is partnering with the US Council of State and Territorial Epidemiologists to develop a uniform definition for measles deaths 2.
Likely accurate — probability of truth 72%, weighted across 15 claims from 2 independent outlets.