To be fair, my experience has been exclusively with hospitals running a specific EMR with a relatively new-ish (at the time) and difficult to configure billing system. Still, we were expecting to see shortfalls nearly an order of magnitude smaller than what we found.

That the hospitals didn't seem to notice the problem, and upon being told of it, often pushed back against moving to fix the problem, is what gave the impression that they must be running on much larger margins than advertised.