ICD-10-CM 2027
ICD-10 code for persistent mucosal disease
From the official ICD-10-CM alphabetic index entry “Disease, diseased › persistent mucosal (middle ear)”. Page updated September 29, 2026.
About coding persistent mucosal disease
The ICD-10-CM code for persistent mucosal disease is H66.20 (Chronic atticoantral suppurative otitis media, unspecified ear). The official index lists 4 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on H66.20.
Within H66.2, choose H66.20 (unspecified ear) only when documentation doesn't support a more specific option: right ear (H66.21), left ear (H66.22) and bilateral (H66.23).
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.
More specific persistent mucosal disease codes (official index)
Common questions about persistent mucosal disease ICD-10 codes
What is the ICD-10 code for persistent mucosal disease?
- H66.20 — Chronic atticoantral suppurative otitis media, unspecified ear. More specific codes apply when the documentation supports them: H66.22, H66.23, H66.21, H66.23.
What is the ICD-10 code for left persistent mucosal disease?
- H66.22 — Chronic atticoantral suppurative otitis media, left ear.
What is the ICD-10 code for right persistent mucosal disease?
- H66.21 — Chronic atticoantral suppurative otitis media, right ear.
Is H66.20 billable?
- Yes. H66.20 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can H66.20 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict H66.20 as a principal diagnosis.
Is H66.20 a CC or MCC?
- No. H66.20 is neither a CC nor an MCC under MS-DRG v44.0.