Nontuberculous mycobacteria (NTM) are bacteria found in soil, dust, and water. NTM do not include M. tuberculosis (the cause of tuberculosis) or M. leprae (the cause of Hansen's disease). Anyone can get an NTM infection but people with underlying lung disease or weakened immune systems are at increased risk. NTM most commonly affects the lungs (pulmonary infection), however, extrapulmonary NTM infections appear to be increasing and are often associated with severe disease and poor outcomes. Extrapulmonary NTM infections are a cause of both sporadic and healthcare-associated infections in the United States. Outbreaks have been associated with medical devices, cosmetic procedures, contaminated parenteral medications, and medical tourism, as well as with community exposures such as tattoo parlors and nail salons.