H65.1 vs H66.9
H65.1 and H66.9 can never be reported together. ICD-10-CM declares them mutually exclusive with an Excludes1 note, meaning the two conditions cannot occur in the same patient — so exactly one of them is correct for any given encounter.
The official note, declared on H65.1
otitis media (acute) NOS (H66.9)
H65.1
Other acute nonsuppurative otitis media
Not billable
- Chapter 8
- Diseases of the ear and mastoid process
- Section
- H65-H75
H66.9
Otitis media, unspecified
Not billable
- Chapter 8
- Diseases of the ear and mastoid process
- Section
- H65-H75
Use when the record says
- Otitis media NOS
- Acute otitis media NOS
- Chronic otitis media NOS
Indexed under
- Otitis › media (acute)
Excludes1 is not always absolute: where two conditions covered by the note are genuinely unrelated, CMS guidance permits reporting both. Document the reasoning rather than assuming it. More on Excludes1 vs Excludes2 · FY2027