I had something similar happen to me. I was on the Big 3 taking meds every other day with Sunday off. I did that for 14 months, which was 11 months after a negative bronchoscopy sample. I had to stop because I got neuropathy in my feet that was getting progressively worse and starting to affect my hands and arms. I also got bad tinnitus from the azithromycin. Due to the worsening side effects my ID doctor thought it was safe to stop early. Just like you, the MAC came back 3 months later. At that point, my ID doctor wanted to put me on azithromycin, rifabutin, and inhaled arikayce on an every day basis. He had me start the azithromycin the first week, then the rifabutin the second week and wanted me to start the arikayce the third week after which time I would be taking all of them every day. After I started the rifabutin, it made me so sick I couldn't get out of bed. I actually wound up in the hospital a couple of times. I never got to the point of taking the arikayce. I had to switch ID doctors because the one I was seeing closed his practice and moved out of state. After reviewing my case and my CT, my new ID doctor said I could try the watch and wait protocol because I was actually feeling fine with no cough or any other negative symptoms. So that's what I've been doing and, of course, airway clearance twice a day nebulizing 7% saline and aerobika combined as well as an AFFLO vest. I also try to get exercise in by walking 2 - 3 miles a day when my autoimmune condition allows. It's very frustrating to go through all that drug therapy only to have the MAC return so soon. I will say that my doctors told me I should do airway clearance, but they never explained what that meant so I didn't know and didn't do much when I was being treated. Since finding this group, I have learned so much and I'm very thankful for that. I had to ask my doctor to prescribe the 7% saline and I had to ask for the vest as well. I would say airway clearance is the most important thing. MAC doesn't like a saline environment so I'm very diligent about keeping up with that twice a day in the hope it will keep it at bay for as long as possible. Hang in there. There are other medication regimens your doctor might prescribe that could work for you.