I have Blue Cross/Blue Shield and Mail Handlers - they paid for everything. But I had the billing person at Cornell University - Dr. Maria New’s office do the forms for me (I am sure it has to be coded right).  If the insurance forms are not filled in correctly - you might need to challenge it with the insurance company. Especially if you filled yourself for a reinbusement. Ask the insurance how to challenge a claim and ask the billing department to resubmit it with the proper codes.