C18Header code — not billable
Malignant neoplasm of colon
- Chapter
- 2. Neoplasms
- Category
- C18
- Effective date
- October 1, 2026
Related codes in category C18
C18.0Malignant neoplasm of cecumYesC18.1Malignant neoplasm of appendixYesC18.2Malignant neoplasm of ascending colonYesC18.3Malignant neoplasm of hepatic flexureYesC18.4Malignant neoplasm of transverse colonYesC18.5Malignant neoplasm of splenic flexureYesC18.6Malignant neoplasm of descending colonYesC18.7Malignant neoplasm of sigmoid colonYesC18.8Malignant neoplasm of overlapping sites of colonYesC18.9Malignant neoplasm of colon, unspecifiedYes
Frequently asked questions
What is ICD-10 code C18?
C18 is an ICD-10-CM diagnosis code for Malignant neoplasm of colon.
Is C18 a billable code?
No. C18 is a category/header code, not billable on its own — use one of its more specific child codes instead.
What ICD-10-CM chapter is C18 in?
C18 falls under Chapter 2: Neoplasms.
When did C18 become effective?
C18 has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.
What other codes are related to C18?
C18 belongs to category C18, which includes 10 other codes — see the related codes list on this page.
ICD-10-CM data maintained by CDC/CMS (public domain). Always verify codes with authoritative sources before making coding or billing decisions.