C18
C18 — Malignant neoplasm of colon
Non-billable headerICD-10-CM
C18 is a non-billable header ICD-10-CM code for malignant neoplasm of colon. It cannot be billed on its own: choose one of the more specific child codes below.
Excludes1 — never code together
These conditions cannot occur together. Billing both on the same encounter is a denial.
- malignant carcinoid tumors of the colon (C7A.02-)
Other codes that can never be billed with C18
These codes carry an Excludes1 note pointing at C18. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading C18 alone.
- C17.2Malignant neoplasm of ileum
Risk adjustment
C18 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.
Code to one of these instead C18
10 child codes. Green means billable.
- C18.0Malignant neoplasm of cecum
- C18.1Malignant neoplasm of appendix
- C18.2Malignant neoplasm of ascending colon
- C18.3Malignant neoplasm of hepatic flexure
- C18.4Malignant neoplasm of transverse colon
- C18.5Malignant neoplasm of splenic flexure
- C18.6Malignant neoplasm of descending colon
- C18.7Malignant neoplasm of sigmoid colon
- C18.8Malignant neoplasm of overlapping sites of colon
- C18.9Malignant neoplasm of colon, unspecified
Questions about C18
- Is C18 a billable ICD-10-CM code?
- No. C18 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
- Where does C18 sit in the tabular list?
- Neoplasms (C00-D49), in the block Malignant neoplasms of digestive organs (C15-C26).
- What cannot be coded together with C18?
- C18 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.