The United States successfully eliminated measles decades ago by taking measures to ensure the virus stopped spreading consistently within the country — but now, it's likely that measles is back.

Toward the end of 2025, experts cautioned that the U.S. could lose its "measles elimination status" within months as various outbreaks raged across the country. If the U.S. does officially lose this status — meaning the country will have experienced sustained measles spread for over a year — it would join a list of countries, including the U.K. and Canada, that have also seen local resurgences of measles as their vaccination rates have declined.