I have had two outpatient surgery claims denied by a Medicare advantage plan as duplicate. We billed cpt code 15823 and the hospital billed the same cpt codes. When I called the claims department, I was told that we needed to check the way we were billing for a possible modifier needed and to check CMS website. Has anyone ever had heard of this? Since it is two different entities/NPI's and TAX ID numbers i wouldn't think there would be a problem