C4A
Non-billableMerkel cell carcinoma
C4A is the ICD-10-CM code for Merkel cell carcinoma. It is a non-billable category code — use a more specific child code such as C4A.0 for billing.
- Status
- Header (non-billable)
- Chapter
- C00-D49
- Subcodes
- 10
- Edition
- FY2026
C00-D49 Neoplasms
What this means — in plain language
MedlinePlus · NIHSkin cancer is the most common form of cancer in the United States. The two most common types are basal cell cancer and squamous cell cancer. They usually form on the head, face, neck, hands, and arms. Another type of skin cancer, melanoma , is more dangerous but less common. Anyone can get skin cancer, but it is more common in people who : Spend a lot of time in the sun or have been sunburned Have light-colored…
Read more about Skin Cancer at MedlinePlus ↗Source: U.S. National Library of Medicine (MedlinePlus). Informational only — not medical advice.
Frequently asked questions
Source: CMS ICD-10-CM FY2026. For informational purposes only — not medical advice. See our medical disclaimer.
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