Negotiated Rate vs CPT Order of Coding

Does anyone have any opinion or factual information on an issue we are having with some payers?

Normally payers pick up a higher RVU CPT as primary when it is billed with another CPT.

When a provider has a negotiated fee with a specific CPT code which happens to be the primary surgical procedure, shouldn't that CPT be paid primary even if a higher RVU code is billed on the same claim?

My situation is, we have a negotiated fee for a Sleeve Gastrectomy (43775). It is sometimes billed with a Hiatal Hernia Repair (43281,59). Even though 43775 is our primary procedure, the payers are paying the 43281 primary and discounting our 43775 which is resulting in an underpayment.

We are trying to figure out if a negotiated fee takes precedent over a higher RVU code on a multiple billing scenario.

Any thoughts would be appreciated. Thank you

Negotiated Rate vs CPT Order of Coding