Billing "mistakes" seem to be standard practice. I went through surgery at the Stanford Hospital, using Stanford's insurance. Prior to the surgery, they charge

Billing "mistakes" seem to be standard practice. I went through surgery at the Stanford Hospital, using Stanford's insurance. Prior to the surgery, they charged me $2000, the out of pocket maximum. Then, a couple of weeks post-surgery. I got another $250 bill. I had to spend the whole day on the phone first with the hospital, then the insurance, and then the hospital. Turns out, that all I had to pay was $250, that the hospital had made a mistake in billing me $2000 at the door. I got my money back a month later. I would normally attribute this to ineptitude. But the frequency and scale with which this happens, reeks of widespread scams.