C4A
ICD-10Non-billable categoryMerkel cell carcinoma
Official ICD-10-CM descriptor (FY2026)
Merkel cell carcinoma
C4A is a category heading, not a billable code. CMS does not accept it on a claim; report one of the more specific codes beneath it.
More specific codes under C4A
- C4A.0Merkel cell carcinoma of lip
- C4A.1Merkel cell carcinoma of eyelid, including canthuscategory
- C4A.2Merkel cell carcinoma of ear and external auricular canalcategory
- C4A.3Merkel cell carcinoma of other and unspecified parts of facecategory
- C4A.4Merkel cell carcinoma of scalp and neck
- C4A.5Merkel cell carcinoma of trunkcategory
- C4A.6Merkel cell carcinoma of upper limb, including shouldercategory
- C4A.7Merkel cell carcinoma of lower limb, including hipcategory
- C4A.8Merkel cell carcinoma of overlapping sites
- C4A.9Merkel cell carcinoma, unspecified
Where this code sits
- Chapter
- 2. Neoplasms (C00-D49)
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ICD-10-CM FY2026. Centers for Medicare & Medicaid Services (CMS) / National Center for Health Statistics (NCHS), “2026 ICD-10-CM Code Descriptions in Tabular Order” (icd10cm_order_2026.txt). Download the original file from cms.gov. Public domain (US Government work). Descriptors, billable flags and instructional notes on this page are reproduced from that file without modification. Krasyn adds no clinical guidance.