I was hit with a bill for over $10K, with much of that falling on me.
I also used to work in corporate finance and I have a good intuition for how billing works.
Before I even got the bill I mentally prepared myself for it by telling myself that it's going to be a long drawn out process.
I waited and waited and received an initial bill a few months after my hospitalization. It was for the aforementioned amount.
I called and politely asked to have it itemized. Naturally,that took several more months.
The bill was reduced, but the itemization was incorrect, so I asked for a correct itemization.
I went through a few more iterations of this. Each time the bill got lower and lower.
Eventually, I had to pay something like $1.5K out of pocket, which would have been a lot less if I didn't have an HSA.
The whole process took almost a year.
If you ever have to go to the hospital, just assume that it will take forever and nitpick the bill (within reason) and continue to challenge it. They will often give up and reduce your bill. Whatever you do, never pay a bill that is not itemized. As a former finance professional I am shocked that hospitals can get away with this, this would never fly in the B2B world, professionals always push back against "mystery bills" that show just the bottom line number.