Excludes1 pair
H65.1- vs H66.9-
H65.1 and H66.9 are not coded together. ICD-10-CM declares them mutually exclusive with an Excludes1 note — the two conditions are not expected to occur together, so exactly one of them is normally correct for a given encounter. The Official Guidelines carve out one exception: if the two conditions are clearly unrelated to each other, both may be reported.
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 (hemorrhagic) (staphylococcal) (streptococcal)
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