C09Malignant neoplasm of tonsil

C09 is the ICD-10-CM diagnosis code for malignant neoplasm of tonsil. It belongs to block C00-C14 (malignant neoplasms of lip, oral cavity and pharynx) and chapter 2 (neoplasms). It is a header code, so it can't be reported by itself; one of its 4 subcodes must be used instead.

To report this condition, pick the subcode that matches the documentation: C09.0 (lar fossa), C09.1 (lar pillar (anterior) (posterior)), C09.8 (tonsil) and C09.9 (unspecified).

The conditions in its Excludes2 note aren't part of C09, but may be coded alongside it if the patient has both: malignant neoplasm of lingual tonsil (C02.4) and malignant neoplasm of pharyngeal tonsil (C11.1).

Use an additional 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) and 2 more.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.