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Medicare requires new modifier for CRC follow-on colonoscopy claims

Apply modifier KX for CRC follow-on colonoscopy claims starting Feb. 27.
Doctor working on a digital tablet
Doctor working on a digital tablet

Medicare beneficiary cost sharing will no longer apply to the screening colonoscopy following a positive non-invasive stool-based screening test. To unlock this free benefit, providers must properly apply modifier KX starting Feb. 27.

What codes does this apply to?

Providers must append modifier KX (“requirements specified in the medical policy have been met”) to HCPCS codes G0105 and G0121 when the screening colonoscopy follows a positive result from one 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)

What happens if I don’t use the KX modifier?

Medicare will return the screening colonoscopy claim as “unprocessable” and you will receive one of following messages:

  • CARC 16: “Claim/service lacks information or has submission billing error(s)” and RARC N822: “Missing Procedure Modifier(s)” OR
  • RARC N823: “Incomplete/Invalid Procedure Modifier”

Attach modifier KX and resubmit the claim to Medicare.

Should I use modifier KX if I remove polyps?

No. If you remove polyps during a screening colonoscopy following a positive non-invasive stool-based test, report the appropriate CPT code (e.g., 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.

Some Medicare beneficiaries are not aware that Medicare has not fully eliminated the coinsurance responsibility yet when polypectomy is needed during a screening colonoscopy. Medicare beneficiary coinsurance responsibility is 15% of the cost of the procedure from 2023 to 2026. The coinsurance responsibility falls to 10% from 2027 to 2029 and by 2030 it will be covered 100% by Medicare.

Where can I find more information?

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