I worked at a company which was doing medical billing for ambulances among other things.
Essentially, the bills are always inflated so when the settlement comes the providers get 20..50%. The crucial procedure is so called "medical coding" where medical notes (sometimes - scrawled on paper with a pencil) are being turned into bills - and that's where additional codes are getting added and more expensive codes are selected. There are books and guidelines on how to do the coding and some automated logic which "fixes" filled forms to bump the amounts a bit.
If the insurance (less frequently - the patient) pays more - that's just a bonus.
Billing itself gets a small fraction of the bill usually amounting to $20..50, they don't profit from inflated bills directly but the clients would select you on the basis of average settlements. Dispatchers also get little fractions. Things are very different when it comes to helicopter ambulances, where the bill could easily get to hundreds of thousands and everyone involved gets a lot. In fact, all the operators prefer to work with helicopters because of that, everyone involved references ground operations as "crap" or so.
Can't say for whole industry but that's what I've seen at one particular place working with several providers/dispatcher companies.
From what I can remember about the ground reality, a $12K bill would mean that they expected to actually get $3..4K.
A typical ground bill for some particular region the company operated at was settled at $500..$2K while an average helicopter bill was smth around $200K if I remember correctly, with spikes up to $500K.