Reading the other comments is interesting because of the differing responses!
I have MAC that was treated with the Big 3 for 18 months three years ago, but it didn't work. I have CTs every 6 months now to monitor it. A recent questionable CT made me have a bronchoscopy. It confirmed I still have MAC and now have aspergillus too. (The fungus was confirmed in about a week.) My ID doctor firmly recommended I begin voriconazole for the aspergillus for at least 3 months when it will be checked again. He said he will begin retreating the MAC if and when the aspergillus is gone. The voriconazole is giving me lots of side effects.