The number of cases of Legionnaires’ disease (LD) in the U.S. have increased nearly ninefold since 2000^1*.  In 2019, health departments reported almost 9,000 cases of LD in the United States². However, LD is underrecognized and underdiagnosed. A study done in 2021 estimated that the true number of LD cases may be 1.8-2.7 times higher than what is reported³. The number of confirmed LD cases in DC in 2019 was 41. There was a decrease in confirmed LD cases in DC during the COVID-19 pandemic years of 2020 (7 cases) and 2021 (3 cases)^2**. In 2022 there was an increase in confirmed LD cases in DC (37 cases). As of July 2023, there has been 8 confirmed cases of LD in DC**. DC Health encourages healthcare providers to maintain awareness of patients most at risk for legionellosis and to follow the guidelines below for appropriate specimen collection, testing, and management of patients. All cases of legionellosis are required to be reported to DC Health.