 Mycobacterium avium complex MAC and other pulmonary nontuberculous mycobacteria P-NTM are ubiquitous organisms that cause isolated pulmonary disease in otherwise healthy patients with yet undefined susceptibilities. Patients typically present with a history of chronic cough, eventually progressing to hemoptysis, fever, and hypoxia. With half or more of all patients failing standard three-drug therapy, this is an insidious disease with a poor prognosis. Under the natural history protocol of nontuberculous mycobacterial infection NTM; 01-I-0202, 46 patients with diagnosed pulmonary MAC disease, 20 patients with M. abscessus disease, and 14 with other types of mycobacteria M. fortuitum, M. massiliense, M. mucogenicum and M. chelonae are being studied. 