Billing ASC CPT 44361 & 43239. We are having an issue with a particular payer not reimbursing us for 43239 with Modifier 59. The CCI Edits say we can append Modifier 59 on CPT 43239. Anyone else having this issue? If the doctor goes beyond 2nd portion of the duodenum and does a biopsy we are billing 44361 as primary code. If the doctor biopsies prior to the 2nd Duodenum we are billing 43239 with Modifier 59. Anyone see an issue with this scenario?