C09 vs C11.1
C09 (Malignant neoplasm of tonsil) compared with C11.1 (Malignant neoplasm of posterior wall of nasopharynx), from the official CMS tabular data. Both may be reported when both conditions are documented (Excludes2).
Can these codes be reported together?
Yes, when both are documented. C09 carries an Excludes2 note covering C11.1: “malignant neoplasm of pharyngeal tonsil (C11.1)”
Excludes2 marks distinct conditions — both may be reported when both are documented.
Side by side
| C09Malignant neoplasm of tonsil | C11.1Malignant neoplasm of posterior wall of nasopharynx | |
|---|---|---|
| Billing status | Non-billable header | Billable |
| Classification | C00-D49 — Neoplasms (C00-D49) | C00-D49 — Neoplasms (C00-D49) |
| Definition | Malignant neoplasm of tonsil is a non-billable ICD-10-CM category code (C09). | Malignant neoplasm of posterior wall of nasopharynx is a billable ICD-10-CM diagnosis code (C11.1). |
| Includes | — | Malignant neoplasm of adenoid Malignant neoplasm of pharyngeal tonsil |
| Use additional code | code to identify: alcohol abuse and dependence (F10.-) exposure to environmental tobacco smoke (Z77.22) | code to identify: exposure to environmental tobacco smoke (Z77.22) exposure to tobacco smoke in the perinatal period (P96.81) |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources