My 8 year old son was born with chronic renal insufficiency, so as you can imagine, we have an extreme amount of medical bills associated with his care.  Fortunately, for us, we had some great doctors, nurses, and office staff to help prepare us for what was ahead, in not only the medical part of it, but also in reference to the insurance part.  One staff member gave me some great advice," Never pay for anything out of your pocket while fighting the insurance claim.  You will never see the money again.  Instead, call the doctor's office's billing department, and ask them to resubmit the claim.  You may have to do this several times, but if you pay for something that your insurance company is responsible for, you will never see the money again."  I have clung to this advice numerous amount of times in the last 8 years, and nine times out of ten, the insurance company was responsible, and ended up paying the bill.  Keep good records of who you have talked to and on what date, and always remember this key word: RESUBMIT.