Yes, he is seeing a specialist and yes we are at a high elevation in Utah. He does have additional health issues that appear to aggravate the MAC infection, specifically lung scarring from scleroderma, which he lived with and seemed to be at bay for several years. It was not until the past year that the cough, heavy mucus with color and lack of oxygen became extreme. He is now also having upper GI issues and we don't know if this is part of the MAC problem or if it is an additional medical dilemma. He will be seeing gastro next week to find out if there are additional medical problems at play, but the extreme tightening in his upper gut causes breathing to be even more difficult. His current doctors are taking this all seriously and trying to help nail down all that is ailing him, but I found that forums with real people who are experiencing the same types of issues to be the best place to find answers and helpful solutions. Thank you to all who respond.