2026 ICD-10-CM Diagnosis Code Q31.8Other congenital malformations of larynx

ICD-10-CM Codes›Q00-Q99›Q30-Q34›Q31

ICD-10-CM Q31.8
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Q31.8 is a billable ICD-10-CM diagnosis code for other congenital malformations of larynx. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 154 through 156. The code is exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Respiratory congenital malformations.

Code Identity

ICD-10-CM Code
Q31.8
Billable Status
Yes — Valid for Submission
Code Describes
Other congenital malformations of larynx
Short Description
Other congenital malformations of larynx
Same as the full description in the CMS dataset.
Parent Code
Q31
Congenital malformations of larynx

Code Classification

ChapterQ00-Q99Congenital malformations, deformations and chromosomal abnormalities
SectionQ30-Q34Congenital malformations of the respiratory system
CategoryQ31Congenital malformations of larynx
This CodeQ31.8Other congenital malformations of larynx

Present on Admission (POA)Billing

Q31.8 is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Absence of larynx
  • Agenesis of bronchus
  • Agenesis of larynx
  • Agenesis of larynx, trachea and bronchus
  • Agenesis of trachea
  • Anomaly of epiglottis
  • Anomaly of laryngeal and/or tracheal cartilage
  • Atresia of larynx and trachea
  • Bifid epiglottis
  • Congenital absence of bronchus
  • Congenital absence of epiglottis
  • Congenital absence of trachea
  • Congenital anomaly of cricoid cartilage
  • Congenital anomaly of epiglottis
  • Congenital anomaly of hyoid bone
  • Congenital anomaly of thyroid cartilage
  • Congenital atresia of epiglottis
  • Congenital atresia of glottis
  • Congenital atresia of larynx
  • Congenital atresia of trachea
  • Congenital bronchial stenosis
  • Congenital cleft larynx
  • Congenital cleft of posterior cricoid cartilage
  • Congenital cleft thyroid cartilage
  • Congenital cyst of aryepiglottic fold
  • Congenital fissure of epiglottis
  • Congenital laryngeal cyst
  • Congenital laryngotracheoesophageal cleft
  • Congenital malformation of larynx and trachea
  • Congenital malformation of trachea and bronchus
  • Congenital stenosis of larynx
  • Congenital stenosis of larynx, trachea and bronchus
  • Congenital stenosis of trachea
  • Congenital supraglottic stenosis
  • Congenital tracheobronchial stenosis
  • Cyst of epiglottis
  • Cyst of larynx
  • Lack of ossification of hyoid bone
  • Laryngeal cleft type 0
  • Laryngeal cleft type I
  • Laryngeal cleft type II
  • Laryngeal cleft type III
  • Laryngeal cleft type IV
  • Stenosis of bronchus
  • Stenosis of trachea
  • Supraglottic cyst
  • Supraglottic stenosis
  • Vocal cord absent

Tabular List NotesGuidance

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

Inclusion Terms

  • Absence of larynx
  • Agenesis of larynx
  • Atresia of larynx
  • Congenital cleft thyroid cartilage
  • Congenital fissure of epiglottis
  • Congenital stenosis of larynx NEC
  • Posterior cleft of cricoid cartilage

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Absence(of) (organ or part) (complete or partial)
      • cricoid cartilage, congenital
    • Absence(of) (organ or part) (complete or partial)
      • epiglottis, congenital
    • Absence(of) (organ or part) (complete or partial)
      • glottis, congenital
    • Absence(of) (organ or part) (complete or partial)
      • larynx (congenital)
    • Absence(of) (organ or part) (complete or partial)
      • thyroid (gland) (acquired)
        • cartilage, congenital
    • Accessory(congenital)
      • vocal cords
    • Agenesis
      • cricoid cartilage
    • Agenesis
      • epiglottis
    • Agenesis
      • glottis
    • Agenesis
      • larynx
    • Agenesis
      • thyroid (gland)
        • cartilage
    • Anomaly, anomalous(congenital) (unspecified type)
      • aryteno-epiglottic folds
    • Anomaly, anomalous(congenital) (unspecified type)
      • cricoid cartilage
    • Anomaly, anomalous(congenital) (unspecified type)
      • epiglottis
    • Anomaly, anomalous(congenital) (unspecified type)
      • glottis
    • Anomaly, anomalous(congenital) (unspecified type)
      • thyroid (gland)
        • cartilage
    • Anomaly, anomalous(congenital) (unspecified type)
      • union
        • cricoid cartilage and thyroid cartilage
    • Anomaly, anomalous(congenital) (unspecified type)
      • union
        • thyroid cartilage and hyoid bone
    • Anomaly, anomalous(congenital) (unspecified type)
      • union
        • trachea with larynx
    • Anomaly, anomalous(congenital) (unspecified type)
      • valleculae
    • Atresia, atretic
      • cricoid cartilage
    • Atresia, atretic
      • epiglottis
    • Atresia, atretic
      • glottis
    • Atresia, atretic
      • larynx
    • Atresia, atretic
      • thyroid cartilage
    • Cleft(congenital)
      • cricoid cartilage, posterior
    • Cleft(congenital)
      • thyroid cartilage
    • Constriction
      • larynx
        • congenital
    • Constriction
      • larynx
        • congenital
          • specified NEC
    • Cyst(colloid) (mucous) (simple) (retention)
      • congenital NEC
        • epiglottis
    • Cyst(colloid) (mucous) (simple) (retention)
      • congenital NEC
        • larynx
    • Deformity
      • cricoid cartilage (congenital)
    • Deformity
      • epiglottis (congenital)
    • Deformity
      • larynx (muscle) (congenital)
    • Deformity
      • thyroid (gland) (congenital)
        • cartilage
    • Elongated, elongation(congenital)
      • petiolus (epiglottidis)
    • Fissure, fissured
      • epiglottis (congenital)
    • Fissure, fissured
      • larynx
        • congenital
    • Imperfect
      • closure (congenital)
        • cricoid cartilage
    • Imperfect
      • closure (congenital)
        • glottis
    • Imperfect
      • closure (congenital)
        • larynx
    • Laryngofissure
      • congenital
    • Malposition
      • congenital
        • epiglottis
    • Malposition
      • congenital
        • glottis
    • Malposition
      • congenital
        • larynx
    • Malposition
      • congenital
        • thyroid (gland) (tissue)
          • cartilage
    • Obstruction, obstructed, obstructive
      • larynx NEC
        • congenital
    • Stenosis, stenotic(cicatricial)
      • larynx
        • congenital NEC
    • Stricture
      • larynx
        • congenital NEC

Clinical ClassificationClinical

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

CCSR MAL007
Respiratory congenital malformations
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Birth Defects

A birth defect is a problem that happens while a baby is developing in the mother's body. Most birth defects happen during the first 3 months of pregnancy. One out of every 33 babies in the United States is born with a birth defect.

The full article covers:

  • What are birth defects?
  • What causes birth defects?
  • Who is at risk of having a baby with birth defects?
  • How are birth defects diagnosed?
  • What are the treatments for birth defects?
  • Can birth defects be prevented?

Read the full article at MedlinePlus

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

Convert Q31.8 to ICD-9-CMHistory

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

ICD-9-CM
748.3 Laryngotrach anomaly NEC
Approximate The match is approximate rather than exact.

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 Q31.8Overview

Is Q31.8 (Congenital malformations of larynx) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other congenital malformations of larynx on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does Q31.8 group to?

When other congenital malformations of larynx is the principal diagnosis on an inpatient stay, it groups to MS-DRG 154, 155, 156, with relative weights from 0.6911 to 1.5635 depending on complications. Higher weights mean higher Medicare reimbursement.

Is Q31.8 exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for other congenital malformations of larynx on inpatient claims.

What is the ICD-9 equivalent of Q31.8?

Under the General Equivalence Mappings, other congenital malformations of larynx converts to ICD-9-CM 748.3 (laryngotrach anomaly NEC). The mapping is approximate, so confirm the match fits the documentation.

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.