Mycobacterium abscessus has emerged as 1 of the most challenging pathogens in pulmonary medicine. Once considered a predominantly environmental organism, it is now widely recognized as a major cause of nontuberculous mycobacterial pulmonary disease, particularly in vulnerable populations with preexisting lung conditions such as cystic fibrosis and brochiectasis. Moreover, M. abscessus also can cause a range of extrapulmonary infections. The organism’s intrinsic and acquired resistance to a broad spectrum of antimicrobial agents necessitates prolonged treatment courses of more than 12 months, and it is associated with poor outcomes, making M abscessus a clinical problem of growing global concern. At the same time, observations over the past decade have raised the possibility that, in addition to environmental acquisition, transmission between patients may occur under certain conditions…