Skip to content
Dx

ICD-10-CM 2027 diagnosis code

C13.1Malignant neoplasm of aryepiglottic fold, hypopharyngeal aspect

✓ Billable / specific

C13.1 is a valid, billable ICD-10-CM code for malignant neoplasm of aryepiglottic fold, hypopharyngeal aspect. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.Short description: Malig neoplasm of aryepiglottic fold, hypopharyngeal aspect

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About C13.1

C13.1 is the ICD-10-CM diagnosis code for malignant neoplasm of aryepiglottic fold, hypopharyngeal aspect. It belongs to category C13 (malignant neoplasm of hypopharynx), block C00-C14 (malignant neoplasms of lip, oral cavity and pharynx) and chapter 2 (neoplasms). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within C13 (malignant neoplasm of hypopharynx), C13.1 is specifically for malignant neoplasm of aryepiglottic fold, hypopharyngeal aspect. Related codes cover postcricoid region (C13.0), posterior wall of hypopharynx (C13.2), overlapping sites of hypopharynx (C13.8) and unspecified (C13.9).

The conditions in its Excludes2 note aren't part of C13.1, but may be coded alongside it if the patient has both: malignant neoplasm of aryepiglottic fold or interarytenoid fold, laryngeal aspect (C32.1).

Use an additional 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.-) and 1 more.

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 011 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with MCC, relative weight 5.6154), DRG 012 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with CC, relative weight 4.381), DRG 013 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy without CC/MCC, relative weight 2.7307), DRG 146 (Ear, Nose, Mouth and Throat Malignancy with MCC, relative weight 2.1329), DRG 147 (Ear, Nose, Mouth and Throat Malignancy with CC, relative weight 1.3055) and DRG 148 (Ear, Nose, Mouth and Throat Malignancy without CC/MCC, relative weight 0.8008), in Pre-MDC and MDC 03 (Diseases and Disorders of the Ear, Nose, Mouth and Throat), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

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

Before ICD-10, this condition was coded in ICD-9-CM as 148.2 (malignant neoplasm of aryepiglottic fold, hypopharyngeal aspect).

Coding notes

Applicable toConditions and synonyms classified to this code
  • 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
Excludes2Not included here — may be reported together if both conditions exist
  • malignant neoplasm of aryepiglottic fold or interarytenoid fold, laryngeal aspect (C32.1)

Notes that apply from higher levels

Instructions written at a parent level also apply to C13.1.

› From C13 Malignant neoplasm of hypopharynx
Excludes2
  • malignant neoplasm of pyriform sinus (C12)
Use additional code
  • 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)

Broader instructions also apply from Chapter 2: Neoplasms.

Table of Drugs & Neoplasms entries

Codes whose notes reference C13.1

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

ICD-9-CM equivalent

Converter →
  • 148.2Malignant neoplasm of aryepiglottic fold, hypopharyngeal aspectexact

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about C13.1

Is C13.1 billable?

Yes. C13.1 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can C13.1 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict C13.1 as a principal diagnosis.

Is C13.1 a CC or MCC?

No. C13.1 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does C13.1 group to?

C13.1 is used in the MS-DRG v44.0 logic for MS-DRG 011 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with MCC), MS-DRG 012 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy with CC), MS-DRG 013 (Tracheostomy for Face, Mouth and Neck Diagnoses or Laryngectomy without CC/MCC), MS-DRG 146 (Ear, Nose, Mouth and Throat Malignancy with MCC), MS-DRG 147 (Ear, Nose, Mouth and Throat Malignancy with CC) and MS-DRG 148 (Ear, Nose, Mouth and Throat Malignancy without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

What is the ICD-9 code for C13.1?

The CMS General Equivalence Mappings map C13.1 to ICD-9-CM 148.2.