C18 vs C7A.02
C18 (Malignant neoplasm of colon) compared with C7A.02 (Malignant carcinoid tumors of the appendix, large intestine, and rectum), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. C18 carries an Excludes1 note covering C7A.02: “malignant carcinoid tumors of the colon (C7A.02-)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Side by side
| C18Malignant neoplasm of colon | C7A.02Malignant carcinoid tumors of the appendix, large intestine, and rectum | |
|---|---|---|
| Billing status | Non-billable header | Non-billable header |
| Classification | C00-D49 — Neoplasms (C00-D49) | C00-D49 — Neoplasms (C00-D49) |
| Definition | Malignant neoplasm of colon is a non-billable ICD-10-CM category code (C18). | Malignant carcinoid tumors of the appendix, large intestine, and rectum is a non-billable ICD-10-CM category code (C7A.02). |
| Use additional code | — | code to identify any associated endocrine syndrome, such as: carcinoid syndrome (E34.00) |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources