Hello Terri, Speaking of susceptibility tests. I was first diagnosed with MAC in Sept 2019 from a bronchoscopy culture performed at the same hospital. I was surprised that a susceptibility test was not done, but I started the big 3 anyway. This past May another culture (sputum sample) was sent to Quest laboratories and I insisted that susceptibility testing be done at the same time and my Dr said he would order that. 8 weeks later my culture is still positive for MAC and M. abscessus as well, but the susceptibility test was never done. He then started me on Arikayce. I am seeing an Infectious disease doctor in 2 days and I want to get another culture sent to NJH this time to include a susceptibility test. I checked the NJH website and they have a total of 11 different varieties of susceptibility tests for NTMs.