It can vary based upon the employer. It could be a self insured group plan.
No, the employer or plan type does not play a part in calculations:
Usual, customary and reasonable is the maximum amount the insurer will consider eligible for reimbursement under a
health insurance
plan. This amount is determined
based on a review of the prevailing charges made by peer physicians for a particular health service within a specific community or geographical area. Commonly UCR is set at a certain percentage of all charges made by providers of similar services or supply, most often at the 80th-90th percentile.Insurers are allowed to define “eligible expense” or “maximum allowable expense” within the policy and to determine the method used to calculate payment for non-participating provider claims, including the percentile of usual and customary that will be paid. I used to work at 3 biig carriers so I know how U&C works and the sneakiness behind it. Some states tried to enact laws against carriers doing this but none have succeeded, there has to be a formula for carriers to limit doctors from inflating bills.. What you can do as a biller..??
If you have a lot of high dollar claims.. not only should you verify benefits but you want to do what's called a Pre-determination of benefits. Carriers WILL not disclose U&C over the phone, they are not allowed to. When you do a pre-determination the carrier will give you (in writing) a response that YES the claim falls within their U&C fee or NO it is $XXX.XX over the U&C. That will give YOU a heads up and the patient too.
Now to appeal U&C is not so cut/dry. The carrier holds the cards, however the claims examiners DO have some sort of administrative authority.. For example; let's say you have an $800 charge that $200 was denied as being over U&C. When you do your appeal you need to include SOMETHING with the appeal that was not submitted the first time around that will cause the claim to get looked at for extenuating circumstances.. most often that would be the operative report or even the office notes. If there is nothing out of the ordinary to prove your appeal, there's still no loss by doing a simple letter of appeal, in some cases the carrier will allow the full amount that was denied the first time and sometimes they will Partially reimburse a little more. Technically speaking the provider does NOT have to do the appeal, however they do have to make the effort to give the patient what they need to do the appeal. As someone who has worked as a claims examiner I can tell you that the patient holds MORE clout with the carrier than the provider (just the way it is) a typical response to a patient calling to complain about the amount not covered is to have them complain to the carrier, however I can tell you when the patient calls the carrier, they will explain how U&C is calculated and the provider will look like the crook

I know this because we were trained on how to do that. So my best advice is to be the good guy and file the appeal as a courtesy to the patient. Bill the excess charges and include a message/note that you will appeal the charge as a courtesy. This gives the patient a heads up and they can follow-up but at same time they are responsible for the excess fees.
Again.. prevention is best.. have the biller or someone in get efficient and get pre-determination's done so that you can avoid these surprises.
Hope this somehow explains it..