C12Billable, valid for claims from October 1, 2026

Malignant neoplasm of pyriform sinus

In Malignant neoplasms of lip, oral cavity and pharynx (C00-C14), chapter 2: Neoplasms

  • C12 is billable and valid on claims for FY 2027. If the record has more detail, check the other codes under C00-C14 below.
  • As a secondary diagnosis it is not a CC or MCC, so it doesn't raise the MS-DRG payment.
  • Counts toward HCC 21 (Lymphoma and Other Cancers) in the Medicare Advantage risk model (CMS-HCC V28).
  • AHRQ's Chronic Condition Indicator classes it as chronic: expected to last 12 months or longer and to limit daily life or need ongoing care.
  • 59 US deaths in 2024 had an underlying cause in category C12, per the National Vital Statistics System on CDC WONDER. Death records use WHO ICD-10, so the count is for the whole category.

Advertisements

Instructional notes

Includes: conditions that are coded here

  • Malignant neoplasm of pyriform fossa

Use additional code: add a second code for this, listed after this one

  • code to identify:
  • 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)

Official coding guidelines

From the ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027 (CMS and NCHS). Links open the PDF at the right page.

Rules for coding benign and malignant neoplasms: using the Neoplasm Table, sequencing primary and secondary sites, treatment encounters, complications, and current cancer versus personal history.

Read Section I.C.2 (page 32), 12 more topics

C12 MS-DRGs

This code does not group to an MS-DRG as a principal diagnosis.

Related conditions

Grouped by AHRQ's Clinical Classifications Software Refined (CCSR), which sorts every diagnosis code into clinically meaningful categories.

C12 is in Head and neck cancers - hypopharyngeal (NEO006, its default category), with 6 codes. Others in it:

  • C13.0 Malignant neoplasm of postcricoid region
  • C13.1 Malignant neoplasm of aryepiglottic fold, hypopharyngeal aspect
  • C13.2 Malignant neoplasm of posterior wall of hypopharynx
  • C13.8 Malignant neoplasm of overlapping sites of hypopharynx
  • C13.9 Malignant neoplasm of hypopharynx, unspecified

Other codes that refer to C12

Notes on these codes point to C12.

  • C13 Excludes2: malignant neoplasm of pyriform sinus (C12)

About the condition

Plain-language background from MedlinePlus (National Library of Medicine), not coding guidance.

Throat Cancer

Throat cancer is a type of head and neck cancer. Throat cancer has different names, depending on which part of the throat is affected. The different parts of your throat are called the oropharynx, the hypopharynx, the nasopharynx, and the larynx, or voice box.

Read more about throat cancer on MedlinePlus

Code history

Valid since FY2016, when ICD-10-CM took effect on October 1, 2015. No changes since.

ICD-9-CM equivalent

Legacy crosswalk from the CMS General Equivalence Mappings (last updated 2018).

  • 148.1 Malignant neoplasm of pyriform sinus
ICD-9 to ICD-10 converter