When I ordered my first batch of supplies, I received an itemized bill from the medical supply company. I was curious to find out why my insurance provider only paid for some items and not others, so I called them and found out that they have a contract with a different company to cover my supplies at 100%!
I've been ordering from the other company ever since and have never received a bill. So, it's definitely worth calling your insurance provider to ask them who they have a contract with, and it will save you a lot of money.