Gastroenterology Coding Alert

Question: Our surgeon performed a screening colonoscopy for a Medicare patient, but found and treated a polyp during the procedure, which pathology later reported as benign. If we use the screening diagnosis code we don’t get paid. What should we do?

Nebraska Subscriber

Answer: Medicare has made it clear that if a patient presents for a screening colonoscopy, you must report a Z code such as Z12.11 (Encounter for screening for malignant neoplasm of colon) on the claim, even if the surgeon finds and treats other problems during the procedure.

When the physician finds and treats a problem, you can no longer report the G codes (G0104-G0105, Colorectal cancer screening) for the screening colonoscopy. But you do still need to list the Z code as the patient’s primary diagnosis in box 21 of the CMS-1500 claim form.

Tip: Just because the Z code is your primary diagnosis, however, does not mean that you have to link that diagnosis in the first position on your claim. Medicare expects coders to follow the coding guidelines for diagnosis codes, but the line-by-line links do not have to be in that order.

To avoid denials, you should list the polyp diagnosis code (D12.-, Benign neoplasm of colon, rectum, anus and anal canal) in the first position to describe the medical necessity for the service.

Alternative: Of course, the definition of a screening colonoscopy is a colonoscopy for a patient that presents without symptoms. If this was really a diagnostic colonoscopy because the patient was having pain or bleeding due to his diverticulosis, that changes the coding and reimbursement entirely.

In that case, you should code a colonoscopy with polypectomy (such as 45384, Colonoscopy, flexible; with removal of tumor[s], polyp[s], or other lesion[s] by hot biopsy forceps) and attach the diverticulosis (K57.30, Diverticulosis of large intestine without perforation or abscess without bleeding) and colon polyp (D12.-) diagnoses.