As of mid-September 2026, confirmed U.S. measles cases have reached 3,294—already exceeding the full-year 2025 total of 2,289—with weekly triple-digit increases driven primarily by large outbreaks in Pennsylvania (676 cases) and sustained transmission in Utah, South Carolina, and other states. CDC data show 95% of cases involve unvaccinated or unknown-status individuals, 63% affect children and teens, and 8% require hospitalization, reflecting the virus’s high contagiousness via airborne spread and the impact of declining MMR coverage. Official counts exclude two Pennsylvania measles-associated infant deaths pending further review, and 38 outbreaks have been reported. Weekly CDC updates and state surveillance reports through year-end will determine the final tally, with school reopenings and seasonal indoor mixing likely to influence further spread.