My first CT was 2013 after an abnormal chest X-ray. Radiologist’s impression was MAC due to nodules & Bronchiectasis. However, cultures done during bronchoscopy grew nothing. Over the years follow-up CT’s showed mild progression with radiologist saying probable MAC, follow-up bronchoscopies (which I believe are more reliable than sputum that you cough up) were always negative. My symptoms remained minimal. And my understanding is that docs are not supposed to treat with the MAC meds unless you grow the bacteria, plus sensitivity studies need to be done on your bacteria to make sure your bug isn’t resistant to drug they prescribe. Finally in early 2023 my CT showed progression into all 5 lobes, and my culture from bronchoscopy was positive. So it took 10 years for me to have a positive culture. I am currently taking Ethambutol and Azithromycin (couldn’t tolerate Rifampin or Rifabutin). I think this disease is tricky and the medications can have serious side effects. Just like doctors shouldn’t prescribe antibiotics for strep unless you have a positive throat culture, even though it looks like strep, I think they have to be careful prescribing for MAC. Glad you’re feeling better.