The ongoing U.S. measles surge, driven by sustained community transmission in multiple states with low vaccination coverage, has produced 1,842 confirmed cases as of May 7, 2026, according to CDC surveillance, with 93 percent tied to outbreaks that began in 2025 or earlier. Most infections continue to occur among unvaccinated individuals, consistent with historical patterns where immunity gaps below the 95 percent threshold enable rapid spread. The CDC has flagged rising risk through late spring and summer due to increased domestic and international travel, which historically accelerates case counts in this timeframe. Weekly reporting from state health departments and CDC briefings through the end of May will determine whether cumulative 2026 totals cross key thresholds by month’s end, as new model projections and vaccination uptake data become available.