Mycobacterium sherrisii was first described as a novel species in 2004 but recently has begun to be more formally recognized with the use of new sequencing techniques. There have only been about 10 cases reported internationally, and we report the first case of M sherrisii in the United States. The mycobacterium was isolated from acid-fast bacilli cultures of a specimen obtained from a bronchoalveolar lavage and blood in a newly diagnosed HIV-infected, US-born patient presenting with sepsis. The patient was started on streptomycin, ethambutol, azithromycin, and rifampin with an improved clinical course. This report indicates the clinical presentation along with the varying drug susceptibilities to the emerging M sherrisii .