medicare's guidelines are 88% while resting...89% if you have another condition, (cor pulmonale, pulmonary hypertension, etc..) You can also be qualified via overnight study, medicare requires <89% for >5 min. Most commercial carriers are different..they can be talked into covering SATs in the 90's if your doc pushes them and your HME company is aggresive in representing you. I actually got someone authorized with a SAT of 94% once because the doctor wouldn't let them go home from the hospital until they got O2. Clincally speaking....Medicare's guidelines are pretty much the gold standard of when you need O2.