Ongoing measles transmission in under-vaccinated communities continues to drive U.S. case counts, with the CDC reporting 2,073 confirmed cases as of June 11, 2026—already approaching the full-year 2025 total of 2,288. Ninety-three percent of 2026 cases link to 30 outbreaks, predominantly among individuals unvaccinated or with unknown MMR status, reflecting sustained endemic circulation after the Americas lost elimination status in late 2025. Recent weekly additions of 40–60 cases underscore active chains in multiple states, though public health containment and seasonal patterns may moderate further growth before June 30. CDC’s weekly surveillance updates, including any new outbreak declarations or revised counts, represent the key near-term data releases that could shift trader-implied probabilities on final June totals.