General Surgery Coding Alert

Question: A patient had a screening colonoscopy in which our surgeon found and removed multiple adenomatous polyps. The patient’s primary physician ordered the patient to return to our surgeon for a six-month “screening surveillance” colonoscopy, which he ordered with a diagnosis of personal history of adenomatous polyp. Our surgeon performed the second colonoscopy with no findings that required tissue removal. What code should we use for the second colonoscopy, and should we use a modifier such as 33 or PT?

Oregon Subscriber

Answer: You should bill the second colonoscopy as 45378 (Colonoscopy, flexible; diagnostic, including collection of specimen[s] by brushing or washing, when performed [separate procedure]). You should assign the diagnosis code as Z86.010 (Personal history of colonic polyps).

Even if the ordering physician calls this a “screening,” colonoscopy, Medicare and most other payers would not consider this a screening, because it exceeds the frequency limitation. Rather, this is actually a surveillance colonoscopy in a patient with known disease. Even for a “high risk” patient, such as one with a history of colonic polyps, Medicare covers the service once every two years.

If your surgeon had performed the second colonoscopy after two years, you would have billed the procedure as G0105 (Colorectal cancer screening; colonoscopy on individual at high risk -- once every two years for high risk), still using ICD-10 code Z86.010, not screening code Z12.11 (Encounter for screening for malignant neoplasm of colon).

Regarding the modifiers, you should not use either PT (Colorectal cancer screening test; converted to diagnostic test or other procedure) or 33 (Preventive services) in this case.

You would use the PT modifier in cases such as your surgeon’s initial colonoscopy involving a screening colonoscopy that turned diagnostic because of abnormal findings.

Reserve the 33 modifier for billing non-Medicare payers with a diagnostic colonoscopy CPT^® code to indicate to the payer that the service is actually for a screening test.