Q16.5 Congenital malformation of inner ear

The ICD-10-CM code for Congenital malformation of inner ear is Q16.5 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

17: Congenital malformations, deformations and chromosomal abnormalities (Q00-QA0)

Section

Q10-Q18: Congenital malformations of eye, ear, face and neck (Q10-Q18)

Category Q16

8 codes (7 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to Q16.5:

• Mondini's malformation (cochlea)
• Absence (of) (organ or part) (complete or partial) › inner ear, congenital
• Anomaly, anomalous (congenital) (unspecified type) › labyrinth, membranous
• Collapse › labyrinth, membranous (congenital)
• Deformity › organ of Corti (congenital)
• Absence (of) (organ or part) (complete or partial) › labyrinth, membranous
• Agenesis › labyrinth, membranous
• Aplasia › labyrinth, membranous

Inclusion Terms

• Congenital anomaly of membranous labyrinth
• Congenital anomaly of organ of Corti

U.S. Hospital Utilization

• An estimated 190 U.S. inpatient stays in 2023 included Q16.5 among the documented diagnoses.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

Official Coding Guidelines

POA indicator for congenital conditions/anomalies and Q00-Q99 exception

Congenital conditions and anomalies Assign “Y” for congenital conditions and anomalies except for categories Q00- Q99, Congenital anomalies, which are on the exempt list. Congenital conditions are always considered present on admission.

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool
• AHRQ — HCUP National Inpatient Sample, Frequencies by Diagnosis Code (2016–2023)