ICD‑10 Coding Guidelines for Hearing Loss

Sensorineural Hearing Loss (SNHL)

The American Academy of Otolaryngology–Head and Neck Surgery (AAO‑HNS) defines the ICD‑10 codes for SNHL as H90.3 for bilateral loss, H90.4 for unilateral loss with normal hearing on the opposite side, and H90.5 for unspecified SNHL【1】.
AAO‑HNS states that SNHL arises from abnormal function of the cochlea, auditory nerve, or central auditory processing pathways【2, 3】.

The AAO‑HNS lists H90.0 for bilateral CHL, H90.1 for unilateral CHL with normal hearing on the contralateral side, and H90.2 for unspecified CHL【2】.
CHL is caused by impairment of sound transmission through the outer ear, tympanic membrane, or middle ear, according to AAO‑HNS guidance【2, 4】.

The AAO‑HNS assigns H90.6 for bilateral mixed loss, H90.7 for unilateral mixed loss with normal hearing on the opposite side, and H90.8 for unspecified mixed loss【2】.
Mixed loss involves concurrent SNHL and CHL in the same ear, as described by AAO‑HNS【2, 3】.

The AAO‑HNS designates H91.2 for sudden idiopathic hearing loss【2, 3】.
Sudden loss is defined as a rapid‑onset impairment within 72 hours, with a ≥30 dB decrease affecting at least three consecutive frequencies【2, 5】.

Genetics in Medicine notes that the severity of hearing loss ranges from slight (16–25 dB) to profound (≥91 dB)【7, 1】.
Accurate laterality documentation (bilateral vs. unilateral) is essential because different ICD‑10 codes apply, per AAO‑HNS and Genetics in Medicine【1, 8】.
Age‑related (presbycusis) hearing loss in adults ≥50 years should be coded as sensorineural loss with the appropriate laterality code, according to AAO‑HNS【8】.
When a genetic or syndromic etiology is identified, additional codes should be used to specify the underlying cause, as recommended by Genetics in Medicine【7, 6, 9】.
The unspecified hearing loss code H91.90 is appropriate only when the type of loss cannot be determined; it should not be used when audiometry or physical examination defines the loss type【2, 10】.

Using H91.90 in place of a specific type code after audiometric evaluation leads to inaccurate coding; AAO‑HNS advises against this practice【2, 10】.
Tuning‑fork testing and audiometry enable clinicians to differentiate CHL from SNHL, ensuring correct code selection per AAO‑HNS recommendations【2, 3】.
Coding sudden hearing loss without confirming whether the loss is sensorineural or conductive is discouraged; proper evaluation is required according to AAO‑HNS guidance【10, 5】.