| C18 | Malignant neoplasm of colon | NON-BILLABLE CODE |
| C18.1 | Malignant neoplasm of appendix | BILLABLE CODE |
| C18.2 | Malignant neoplasm of ascending colon | BILLABLE CODE |
| C18.3 | Malignant neoplasm of hepatic flexure | BILLABLE CODE |
| C18.4 | Malignant neoplasm of transverse colon | BILLABLE CODE |
| C18.5 | Malignant neoplasm of splenic flexure | BILLABLE CODE |
| C18.6 | Malignant neoplasm of descending colon | BILLABLE CODE |
| C18.7 | Malignant neoplasm of sigmoid colon | BILLABLE CODE |
| C18.8 | Malignant neoplasm of overlapping sites of colon | BILLABLE CODE |
| C18.9 | Malignant neoplasm of colon, unspecified | BILLABLE CODE |
