Hi Tina. I am so sorry to hear that your mac is showing positive again. I believe it is fairly common for a reoccurrence to happen. My Mayo dr that has retired already had told me that maintenance antibiotics should be continued for a good while after coming off of the Big 3; or it may be that you need to be on them a bit longer. I was taken off of my maintenance meds last Dec, and guess what, I tested positive for MAC after having tested negative since 2014. MAC never truly goes away or stays away. It can be knocked down to an undetectable level to show as a negative test result, that is the sweet spot we all aim for. Are you being super diligent with your saline treatments 2x a day?