C09.9 — Malignant neoplasm of tonsil, unspecified
Is C09.9 billable?
Yes, but C09.9 is an unspecified code. C09.9 is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, C09.9 is an unspecified or catch-all code. Payers apply additional scrutiny to unspecified codes and many deny them when the medical record supports a more specific option, so check the documentation before selecting C09.9 — the more specific alternatives are listed below.
C09.9 at a glance
| Code | C09.9 |
|---|---|
| Description | Malignant neoplasm of tonsil, unspecified |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Which MS-DRGs does C09.9 group to?
C09.9 sits in MDC Pre and helps define the logic of 3 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 011Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with MCCsurgical
- 012Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with CCsurgical
- 013Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy without CC/MCCsurgical
Inclusion terms
Alternative wording in documentation that is classified to C09.9.
- Malignant neoplasm of tonsil NOS
- Malignant neoplasm of faucial tonsils
- Malignant neoplasm of palatine tonsils
Use additional code — inherited from C09
Report an additional code alongside C09.9 to fully describe the condition. C09.9 is sequenced first.
- code to identify:
- alcohol abuse and dependence (F10.-)
- exposure to environmental tobacco smoke (Z77.22)
- exposure to tobacco smoke in the perinatal period (P96.81)
- history of tobacco dependence (Z87.891)
- occupational exposure to environmental tobacco smoke (Z57.31)
- tobacco dependence (F17.-)
- tobacco use (Z72.0)
Excludes2 — not included here — inherited from C09
The conditions below are not part of C09.9, but a patient may have both at the same time. When documentation supports it, C09.9 and the excluded code may both be reported.
How long has C09.9 existed?
C09.9 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.