2026 ICD-10-CM Diagnosis Code C13.1Malignant neoplasm of aryepiglottic fold, hypopharyngeal aspect

ICD-10-CM CodesC00–D49C00-C14C13

ICD-10-CM C13.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

C13.1 is a billable ICD-10-CM diagnosis code for malignant neoplasm of aryepiglottic fold, hypopharyngeal aspect. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 146 through 148. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Head and neck cancers - hypopharyngeal.

Code Identity

ICD-10-CM Code
C13.1
Billable Status
Yes — Valid for Submission
Code Describes
Malignant neoplasm of aryepiglottic fold, hypopharyngeal aspect
Short Description
Malig neoplasm of aryepiglottic fold, hypopharyngeal aspect
Parent Code
Malignant neoplasm of hypopharynx

Code Classification

ChapterC00–D49Neoplasms
SectionC00-C14Malignant neoplasms of lip, oral cavity and pharynx
CategoryC13Malignant neoplasm of hypopharynx
This CodeC13.1Malignant neoplasm of aryepiglottic fold, hypopharyngeal aspect

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Malignant neoplasm of junctional region of epiglottis
  • Malignant tumor aryepiglottic fold - hypopharyngeal aspect
  • Neoplasm of hypopharyngeal aspect of aryepiglottic fold
  • Neoplasm of hypopharyngeal aspect of interarytenoid fold
  • Primary malignant neoplasm of epiglottis
  • Primary malignant neoplasm of hypopharyngeal aspect of aryepiglottic fold
  • Primary malignant neoplasm of hypopharyngeal aspect of interarytenoid fold
  • Primary malignant neoplasm of soft tissues of neck
  • Primary squamous cell carcinoma of aryepiglottic fold
  • Primary squamous cell carcinoma of hypopharyngeal aspect of aryepiglottic fold
  • Primary squamous cell carcinoma of hypopharynx
  • Primary squamous cell carcinoma of supraglottis
  • Squamous cell carcinoma of epiglottis
  • Squamous cell carcinoma of head and neck
  • Squamous cell carcinoma of hypopharyngeal aspect of aryepiglottic fold

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Malignant neoplasm of aryepiglottic fold, marginal zone
  • Malignant neoplasm of aryepiglottic fold NOS
  • Malignant neoplasm of interarytenoid fold, marginal zone
  • Malignant neoplasm of interarytenoid fold NOS

Type 2 Excludes

  • malignant neoplasm of aryepiglottic fold or interarytenoid fold, laryngeal aspect C32.1

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NEO006
Head and neck cancers - hypopharyngeal
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Squamous Cell Carcinoma of Head and Neck

    the most common type of head and neck carcinoma that originates from cells on the surface of the nasal cavity; mouth; paranasal sinuses, salivary glands, and larynx. mutations in tnfrsf10b, pten, and ing1 genes are associated with this cancer.

Table of NeoplasmsClinical

Anatomical sites in the Table of Neoplasms that reference this code family.

SiteMalig.
Primary
Malig.
Secondary
Ca
in situ
BenignUncertainUnspec.
aryepiglottic foldC13.1C79.89D00.08D10.7D37.05D49.0
aryepiglottic fold hypopharyngeal aspectC13.1C79.89D00.08D10.7D37.05D49.0
aryepiglottic fold marginal zoneC13.1C79.89D00.08D10.7D37.05D49.0
interarytenoid foldC13.1C79.89D00.08D10.7D37.05D49.0
interarytenoid fold hypopharyngeal aspectC13.1C79.89D00.08D10.7D37.05D49.0
interarytenoid fold marginal zoneC13.1C79.89D00.08D10.7D37.05D49.0

Patient EducationClinical

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 the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert C13.1 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
148.2 Mal neo aryepiglott fold
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About C13.1Overview

Is C13.1 (Malignant neoplasm of hypopharynx) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report malignant neoplasm of aryepiglottic fold, hypopharyngeal aspect on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does C13.1 group to?

When malignant neoplasm of aryepiglottic fold, hypopharyngeal aspect is the principal diagnosis on an inpatient stay, it groups to MS-DRG 146, 147, 148, with relative weights from 0.7971 to 2.1174 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of C13.1?

Under the General Equivalence Mappings, malignant neoplasm of aryepiglottic fold, hypopharyngeal aspect converts to ICD-9-CM 148.2 (mal neo aryepiglott fold). The mapping is a direct match.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.