C4A
C4A: Merkel cell carcinoma
Non-billable headerICD-10-CM
C4A is a non-billable header ICD-10-CM code for merkel cell carcinoma. It cannot be billed on its own: choose one of the more specific child codes below.
Other codes that can never be billed with C4A
Their own Excludes1 notes name this code, so the conflict is not listed above.
Risk adjustment
No CMS-HCC V28 category: this code does not change a RAF score.
Code history
Unchanged in every release from FY2024 to FY2027.
Code to one of these instead C4A
10 child codes. Green means billable.
- 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
- C4A.9Merkel cell carcinoma, unspecified