C21.1
C21.1 — Malignant neoplasm of anal canal
Billable / specific codeICD-10-CM
C21.1 is a billable, specific ICD-10-CM code for malignant neoplasm of anal canal. It is valid for submission on a claim.
Inclusion terms
Alternative wordings a physician may use in the chart for this same code.
- Malignant neoplasm of anal sphincter
Risk adjustment
C21.1 risk-adjusts. Under the CMS-HCC V28 model it maps to this category:
- HCC 22 Bladder, Colorectal, and Other Cancers0.363 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.
Medicare coverage
C21.1 is named in 103 Medicare coverage policies — 103 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A52450Billing and Coding: Paclitaxel (e.g., Taxol®/Abraxane ™)
- A52450Billing and Coding: Paclitaxel (e.g., Taxol®/Abraxane ™)
- A52479Oral Anticancer Drugs - Policy Article
- A52479Oral Anticancer Drugs - Policy Article
Related codes at this level
Codes that share C21. If C21.1 is not quite right, the correct code is usually one of these.
Questions about C21.1
- Is C21.1 a billable ICD-10-CM code?
- Yes. C21.1 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does C21.1 sit in the tabular list?
- Neoplasms (C00-D49), in the block Malignant neoplasms of digestive organs (C15-C26).