Let's clarify please, when you say MAI do you mean Mycobacteria Avium Intracellulare? If so, the is part of the infective group known as MAC (Mycobacteria Avium Complex) or NTM (Nontubercular Mycobacteria.)
Are your culture still positive after 10 months on your drug regimen? If so, have the sputum samples been submitted for drug sensitivity testing to be sure you are using the correct antibiotics to actually clear the infection?
What sort of improvement are you seeing? Improved CT, less cough, clean culture, etc.

Please excuse my curiosity, but in seven years on Mayo Connect and NTM-ir, I have never seen this particular combination of meds used.