Medicare wants you to use modifiers PT and KX, but not together
CMS uses Healthcare Common Procedural Coding System (HCPCS) codes to differentiate between screening and diagnostic colonoscopies to apply screening benefits. For Medicare beneficiaries who choose colonoscopy as their CRC screening, use HCPCS code G0105 (Colorectal cancer screening; colonoscopy on individual at high risk) or G0121 (Colorectal cancer screening; colonoscopy on individual not meeting the criteria for high risk) for screening colonoscopies as appropriate. No modifier is necessary with G0105 or G0121.
Effective for claims with dates of service on or after 1/1/2023, use the appropriate HCPCS codes G0105 or G0121 with the KX modifier for colonoscopy following a positive result for any of the following non-invasive stool-based CRC screening tests:
• Screening guaiac-based fecal occult blood test (gFOBT) (CPT 82270)
• Screening immunoassay-based fecal occult blood test (iFOBT) (HCPCS G0328)
• Cologuard™ – multi-target stool DNA (sDNA) test (CPT 81528)
According to the guidance in the CMS Manual System, if modifier KX is not added to G0105 or G0121 for colonoscopy following a positive non-invasive stool-based test, Medicare will return the screening colonoscopy claim as “unprocessable.”3 If this happens, add modifier KX and resubmit the claim.
If polyps are removed during a screening colonoscopy, use the appropriate CPT code (45380, 45384, 45385, 45388) and add modifier PT (colorectal cancer screening test; converted to diagnostic test or other procedure) to each CPT code for Medicare. However, it is important to note that if a polyp is removed during a screening colonoscopy, the Medicare beneficiary is responsible for 15% of the cost from 2023 to 2026. This falls to 10% of the cost from 2027 to 2029, and by 2030 it will be covered 100% by Medicare. Some Medicare beneficiaries are not aware that Medicare has not fully eliminated the coinsurance responsibility yet.
