C09.1 Malignant neoplasm of tonsillar pillar (anterior) (posterior)

Billable ICD-10-CM code, FY2026.

Applies from C09 Malignant neoplasm of tonsil

Excludes2 (not included here)

• malignant neoplasm of lingual tonsil (C02.4)
• malignant neoplasm of pharyngeal tonsil (C11.1)

Use additional code

• 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)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 21 — Lymphoma and Other Cancers
• CMS-HCC V22: HCC 11 — Colorectal, Bladder, and Other Cancers
• ESRD V24: HCC 11

MS-DRG index

Defines the logic of DRG(s) 011-013 in MDC PRE.

Approximate ICD-9-CM (GEMs)

• 146.2 Malignant neoplasm of tonsillar pillars (anterior) (posterior)

Code annotations containing back-references to C09.1

Back-references to C09

• Type 2 Excludes: C10 Malignant neoplasm of oropharynx ("malignant neoplasm of tonsil (C09.-)")

Nearby codes

• C09 Malignant neoplasm of tonsil
• C09.0 Malignant neoplasm of tonsillar fossa
• C09.1 Malignant neoplasm of tonsillar pillar (anterior) (posterior) (this code)
• C09.8 Malignant neoplasm of overlapping sites of tonsil
• C09.9 Malignant neoplasm of tonsil, unspecified