C21
Non-billableMalignant neoplasm of anus and anal canal
C21 is the ICD-10-CM code for Malignant neoplasm of anus and anal canal. It is a non-billable category code — use a more specific child code such as C21.0 for billing.
- Status
- Header (non-billable)
- Chapter
- C00-D49
- Subcodes
- 4
- Edition
- FY2026
C00-D49 Neoplasms
What this means — in plain language
MedlinePlus · NIHWhat is anal cancer? Your anus is the opening at the end of your large intestine. It is where stool (poop) leaves your body. The anus is formed partly from your outer layers of skin and partly from your intestine. Anal cancer is a type of cancer that forms in the tissues of your anus. Who is more likely to develop anal cancer? Anyone can get anal cancer, but you are more likely to develop it if you: You have an…
Read more about Anal Cancer at MedlinePlus ↗Source: U.S. National Library of Medicine (MedlinePlus). Informational only — not medical advice.
Excludes2 — not included here
- •malignant carcinoid tumors of the colon (C7A.02-)
- •malignant melanoma of anal margin (C43.51)
- •malignant melanoma of anal skin (C43.51)
- •malignant melanoma of perianal skin (C43.51)
- •other and unspecified malignant neoplasm of anal margin (C44.500, C44.510, C44.520, C44.590)
- •other and unspecified malignant neoplasm of anal skin (C44.500, C44.510, C44.520, C44.590)
- •other and unspecified malignant neoplasm of perianal skin (C44.500, C44.510, C44.520, C44.590)
Medications indicated for this condition
FDA labelingDrugs whose FDA labeling lists this condition's category among its indications. Informational only — not a treatment recommendation or 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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