We have BCBS of ND. We were warned by the vest company that initially coverage would be denied; however, we'd probably get a request for more information regarding DS' health -- hospitalizations, culture results, was he on inhaled antibiotics... So we answered their questions. We were sent the vest, but still didn't know how much would be covered. The vest company explained the whole appeal process to us, indicated they did have financing available.
For the first several months we'd get calls from the vest company asking for the hours on the machine (checking that we were using it). Eventually we got a letter indicating how much we owed -- much less than the 20% I thought we'd have to pay and that the vest was now ours.