C18: Malignant neoplasm of colon
Codes under C18 (Malignant neoplasm of colon). A ✓ marks a billable (fully specified) code; category codes without a ✓ are not billable on their own.
| Code | Description | Billable |
|---|---|---|
| C18.0 | Malignant neoplasm of cecum | ✓ |
| C18.0 | Malignant neoplasm of cecum | ✓ |
| C18.1 | Malignant neoplasm of appendix | ✓ |
| C18.1 | Malignant neoplasm of appendix | ✓ |
| C18.2 | Malignant neoplasm of ascending colon | ✓ |
| C18.2 | Malignant neoplasm of ascending colon | ✓ |
| C18.3 | Malignant neoplasm of hepatic flexure | ✓ |
| C18.3 | Malignant neoplasm of hepatic flexure | ✓ |
| C18.4 | Malignant neoplasm of transverse colon | ✓ |
| C18.4 | Malignant neoplasm of transverse colon | ✓ |
| C18.5 | Malignant neoplasm of splenic flexure | ✓ |
| C18.5 | Malignant neoplasm of splenic flexure | ✓ |
| C18.6 | Malignant neoplasm of descending colon | ✓ |
| C18.6 | Malignant neoplasm of descending colon | ✓ |
| C18.7 | Malignant neoplasm of sigmoid colon | ✓ |
| C18.7 | Malignant neoplasm of sigmoid colon | ✓ |
| C18.8 | Malignant neoplasm of overlapping sites of colon | ✓ |
| C18.8 | Malignant neoplasm of overlapping sites of colon | ✓ |
| C18.9 | Malignant neoplasm of colon, unspecified | ✓ |
| C18.9 | Malignant neoplasm of colon, unspecified | ✓ |
Frequently asked questions
What is ICD-10-CM code C18?
C18 is an ICD-10-CM category covering Malignant neoplasm of colon. It contains 20 more specific diagnosis codes, 20 of which are billable.
Is C18 a billable code?
No — C18 is a category header and isn't billable on its own. Code to the highest level of specificity using one of its subcodes (for example C18.0 — Malignant neoplasm of cecum). 20 of the 20 codes under C18 are billable.
What codes fall under C18?
C18 includes C18.0, C18.0, C18.1, C18.1, C18.2, plus 15 more. See the full list with descriptions and billable status above.
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Informational only, not coding or medical advice. Verify against the official ICD-10-CM (FY2026) and your payer's guidelines.
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