Gastroenterology Coding Alert

Question: A patient had a routine colonoscopy screening done. I coded the screening as diagnostic due to a finding of an anal fissure that the provider chose not to repair. I thought if anything is found during a colonoscopy screening, it’s appropriate to code the diagnostic code 45378 with modifier 33/PT. Is that incorrect? The patient is insisting this was a screening.

AAPC Forum Participant

Answer: CPT^® 45378 (Colonoscopy, flexible; diagnostic, including collection of specimen(s) by brushing or washing, when performed (separate procedure)) is the correct code to report for a non-Medicare patient’s screening if it accurately describes the provider’s technique. Code G0105 (Colorectal cancer screening… high risk) or G0121 (Colorectal cancer screening… not high risk) for Medicare patients. However, appending modifier 33 (Preventive services) or for Medicare, PT (Colorectal cancer screening test; converted to diagnostic test or other procedure), alerts the payer that the screening turned diagnostic, which does not accurately describe what happened in this scenario.

In this case, as in many screening situations, incidental findings are noted and can be coded but do not change the fundamental nature of the procedure. Examples are diverticulosis or internal hemorrhoids. If such findings are coded, they are secondary diagnosis codes, with Z12.11 (Encounter for screening for malignant neoplasm of colon) used as the primary code.

Let’s first start by differentiating a screening from a diagnostic test. “A screening test is a test provided to a patient in the absence of signs or symptoms … for the purpose of testing for the presence of colorectal cancer or colorectal polyps. Whether a polyp or cancer is ultimately found does not change the screening intent of that procedure.” A diagnostic colonoscopy is performed “as a result of an abnormal finding, sign or symptom” (source: https://gastro.org/practice-resources/ reimbursement/coding-faq-screening-colonoscopy/).

If a polyp or lesion is found and then the practitioner removes it, the procedure turns diagnostic and should be coded accordingly. In the above scenario, the provider did not repair the anal fissure. The reason for this is not clear from the information provided; however, “anal fissures do not increase the risk of colon cancer nor cause it,” according to the American Society of Colon & Rectal Surgeons (ASCRS) (https://fascrs.org/patients/ diseases-and-conditions/a-z/anal-fissure#text=Anal fissures do not increase,other causes of rectal bleeding). Repairing an anal fissure is a surgical procedure that would very seldom be done during the same encounter as a colonoscopy. Considering all this, you’ll want to report Z12.11 to justify the procedure, which is coded with 45378. No modifiers are necessary.

Note that when a screening becomes diagnostic (when a polyp is found and removed), federal regulations dictate that the deductible and copay costs are waived for patients with commercial plans. Medicare is also phasing out such charges over the next few years. This applies as well to commercial plan patients whose initial screening was a fecal immunochemical test (FIT) or Cologuard™ who then required a colonoscopy due to abnormal findings.