It is unclear which you mean but I'm going to answer as if you are a billing service looking to determine how much to charge:
We do facility billing for residential facilities. In some cases we have a sliding flat fee schedule per month based on the number of beds that are filled. This works well, especially if the facility is just starting out. The amount of work is directly related to the number of patients they have.
If they are out of network we sometimes set up a relationship where they actually refer the patient to us and we work directly with the patient (of course with the facilities help). In this case we charge the patient a flat fee which includes the submission of the claim, and resubmissions necessary and assistance to them in determining what's happening with their claim. Of course no guarantees that they will be reimbursed with out of network.