C4A.9: Merkel cell carcinoma, unspecified
C4A.9 is a billable, specific ICD-10-CM code for merkel cell carcinoma, unspecified. It is valid for submission on a claim.
Check C4A.9 with the rest of the claim: free scrubberInclusion terms
Alternative wordings a physician may use in the chart for this same code.
- Merkel cell carcinoma of unspecified site
- Merkel cell carcinoma NOS
Other codes that can never be billed with C4A.9
Their own Excludes1 notes name this code, so the conflict is not listed above.
- C44Other and unspecified malignant neoplasm of skin
Risk adjustment
C4A.9 risk-adjusts. Under the CMS-HCC V28 model it maps to this category:
- HCC 21 Lymphoma and Other Cancers0.671 RAF
Coefficient shown for the Community Non-dual Aged segment. A higher HCC in the same hierarchy will suppress this one, so capturing it does not always add score. Look up the whole chart to see which of its HCCs the hierarchy would zero.
Medicare coverage
C4A.9 is named in 41 Medicare coverage policies: 41 listing it as supporting medical necessity. Which one applies depends on your Medicare contractor.
- A52479Oral Anticancer Drugs - Policy Article
- A53101Billing and Coding: MolDX: bioTheranostics Cancer TYPE ID® Update
- A54188Billing and Coding: MolDX: bioTheranostics Cancer TYPE ID®
- A54386Billing and Coding: MolDX: bioTheranostics Cancer TYPE ID® Update
Alphabetic index entries that lead here
- Carcinoma›Merkel cell
Code history
Unchanged in every release from FY2024 to FY2027.
Other codes under C4A
- C4A.0Merkel cell carcinoma of lip
- C4A.1Merkel cell carcinoma of eyelid, including canthus
- C4A.2Merkel cell carcinoma of ear and external auricular canal
- C4A.3Merkel cell carcinoma of other and unspecified parts of face
- C4A.4Merkel cell carcinoma of scalp and neck
- C4A.5Merkel cell carcinoma of trunk
- C4A.6Merkel cell carcinoma of upper limb, including shoulder
- C4A.7Merkel cell carcinoma of lower limb, including hip
- C4A.8Merkel cell carcinoma of overlapping sites