Q31.8
Other congenital malformations of larynx
Q31.8 (also written Q318) is a billable ICD-10-CM diagnosis code for other congenital malformations of larynx. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 7 codes in category Q31 (Congenital malformations of larynx). The Alphabetic Index lists it under 49 entries. Its coding notes include 1 Excludes1 entry and 1 Excludes2 entry.
Guidelines tip
From the FY2027 Official Guidelines. ICD10Ref adds no rules of its own.
Chapter 17 codes can be used for life. Manifestations that are an inherent part of a specifically coded anomaly are not coded separately. A corrected malformation is reported with a personal history code.
Excludes1
Not coded here. The listed conditions generally should not be reported together.
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
Also from chapter/block level (1 note)
- inborn errors of metabolism (E70-E88)
Care settings
How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.
Home Health Primary
Accepted as the primary (principal) diagnosis on a home health claim. The Home Health Grouper assigns it to the MMTA - Other clinical group.
Source: CMS Home Health Grouper Software v07.2.26, effective October 1, 2026Hospital CC
Counts as a complication or comorbidity (CC) when reported as a secondary diagnosis on an inpatient claim. It does not count when the principal diagnosis is one of the 18 codes in its exclusion list. Some MS-DRGs also ignore a CC or MCC that defines the DRG.
Source: CMS MS-DRG Definitions Manual v44, effective October 1, 2026, Appendix CInclusion terms
Conditions classified to this code.
- 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
Notes
Also from chapter/block level (1 note)
- Codes from this chapter are not for use on maternal records
Alphabetic Index terms
Terms the official Alphabetic Index lists for this code. 49 entries
- 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
Show 37 more
- 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