Malignant neoplasm of anus and anal canal (C21) ICD-10-CM
The C21 code range covers malignant neoplasm of anus and anal canal with 5 ICD-10-CM diagnosis codes. 4 of them are billable and valid for claim submission in fiscal year 2027, and the category headers group them but cannot themselves be billed.
Type 2 Excludes
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
- 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
Codes in the C21 Range 5 codes · 4 billable
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the C21 range.
Malignant Anal Canal Neoplasm
A primary or metastatic malignant neoplasm that affects the anal canal.
Malignant Anal Neoplasm
A primary or metastatic malignant neoplasm that affects the anal canal or perianal skin.
About the C21 Code Range
Cancer of the anus or anal canal falls within the digestive-organ cancer group. C21 separates these cancers by site.
C21.0 names the anus without further site detail. C21.1 names the anal canal, and C21.2 names the cloacogenic zone. C21.8 identifies overlapping sites of the rectum, anus, and anal canal.
Questions About This Page
How many billable codes are in the C21 range?
Of the 5 codes in this range, 4 are billable and valid for claim submission from October 1, 2026 through September 30, 2027. Category header codes group them but cannot be reported on claims.
What does the C21 range classify?
The range classifies malignant neoplasm of anus and anal canal. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2027 ICD-10-CM Tabular List and order file, effective October 1, 2026 through September 30, 2027.
