C21.8 Malignant neoplasm of overlapping sites of rectum, anus and anal canal
Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.
Applicable to
- Malignant neoplasm of anorectal junction
- Malignant neoplasm of anorectum
- Primary malignant neoplasm of two or more contiguous sites of rectum, anus and anal canal
Applies from C21 Malignant neoplasm of anus and anal canal
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)
Risk adjustment (HCC)
- CMS-HCC V28: HCC 22 — Bladder, Colorectal, and Other Cancers
- CMS-HCC V22: HCC 11 — Colorectal, Bladder, and Other Cancers
- ESRD V24: HCC 11
MS-DRG index
Defines the logic of DRG(s) 374-376 in MDC 06.
Approximate ICD-9-CM (GEMs)
154.8 Malignant neoplasm of other sites of rectum, rectosigmoid junction, and anus (approximate)
Nearby codes
C21 Malignant neoplasm of anus and anal canalC21.0 Malignant neoplasm of anus, unspecifiedC21.1 Malignant neoplasm of anal canalC21.2 Malignant neoplasm of cloacogenic zoneC21.8 Malignant neoplasm of overlapping sites of rectum, anus and anal canal (this code)