Do you have insurance? They do funny things with the billing as it relates to insurance versus cash.
My son crashed his dirt bike and spent a night in the hospital with a fractured radius and ulna and a concussion once. Being a dumbass teenager he didn't fill out the accident report they sent him and so the claim was denied. The bills started showing up. They totalled about $13K.
I asked my doc, "WTF Mary?". She said it sounded a bit high, like just over double what you'd expect...which ironically is about what I expected. I flew in a helicopter, spent three days in the hospital, had an endoscopic exam, and got released for less money. The bird cost $3500 in case you're wondering. Anyway my son called the insurance company (he's 18 and if he is too lazy to fill out the paperwork I sure as fuck wasn't paying the $13K) and got them to send him a new form. He filled it out and the bills got paid. Not $13K worth of bills though. There were adjustments and this and that and the HMO ended up writing a check for just over $4K...about what I thought it would have really cost.
I think there is some funny tax shit going on. They bill high, settle lower, and write the rest off as a loss or something. It's just a guess though.