The Center for Disease Control Weekly report for March 2023 reports an increase in Babesiosis incidence (Trends in Reported Babesiosis Cases — United States, 2011–2019 | MMWR (cdc.gov)). During 2011–2019, U.S. babesiosis incidence significantly increased in northeastern states. Three states (Maine, New Hampshire, and Vermont) that were not considered to have endemic babesiosis had significantly increasing incidences and reported case counts similar to or higher than those in the seven states (Connecticut, Massachusetts, Minnesota, New Jersey, New York, Rhode Island, and Wisconsin) with known endemic transmission. During 2011–2019, a total of 16,456 cases of babesiosis were reported to CDC by 37 states, including 16,174 (98.2%) reported from the 10 states included in this analysis.