ICD-10-CM Diagnosis Code (2025)
Official Description for C21
Malignant neoplasm of anus and anal canal
Coding Notes & Guidelines for C21
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)
Inclusion Terms
Malignant neoplasm of anal sphincter
Inclusion Terms
- Malignant neoplasm of anorectal junction
- Malignant neoplasm of anorectum
- Primary malignant neoplasm of two or more contiguous sites of rectum, anus and anal canal
Child Codes (More Specific Codes for C21):
About ICD-10-CM Code C21 (Malignant neoplasm of anus and anal canal)
ICD-10-CM code C21 is a billable or specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes. The 2025 edition of ICD-10-CM C21 became effective on October 1, 2024.
This page provides detailed information about C21 - Malignant neoplasm of anus and anal canal. It includes common terminology, coding guidelines such as "Includes," "Excludes1," and "Excludes2" notes, and information on required 7th characters. Utilizing this information correctly is essential for accurate medical coding and claims submission for conditions like Malignant neoplasm of anus and anal canal.