Once we have demonstrated the feasibility of short course therapy and confirm that resistance to macrolides does not develop, we hope to apply for external funding to support a longer term randomized controlled trial comparing "standard" MAC therapy (which usually consists of a period of eighteen to twenty-four months with at least three antimicrobials) to short course (three months) MAC antimicrobial treatment, alternating each year with nine months of non-MAC bronchial hygiene measures for two consecutive years. If a larger study confirms efficacy of this approach, we would then propose even larger multi-site studies to test the hypothesis that short course MAC therapy alternating every year with non-MAC bronchial hygiene therapy should be considered in all adult patients with MAC pulmonary disease associated with multifocal bronchiectasis and multiple small nodules throughout their lives.