A18.6 vs H66.3
A18.6 and H66.3 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 H66.3
tuberculous otitis media (A18.6)
A18.6
Tuberculosis of (inner) (middle) ear
Billable
- Chapter 1
- Certain infectious and parasitic diseases
- Section
- A15-A19
Use when the record says
- Tuberculous otitis media
Indexed under
- Tuberculosis, tubercular, tuberculous › ear (calcification) (calcified) (caseous) (chromogenic acid-fast bacilli) (degeneration) (fibrocaseous) (fistula) (interstitial) (isolated circumscribed lesions) (necrosis) (parenchymatous) (ulcerative)
- Tuberculosis, tubercular, tuberculous › eustachian tube (calcification) (calcified) (caseous) (chromogenic acid-fast bacilli) (degeneration) (fibrocaseous) (fistula) (interstitial) (isolated circumscribed lesions) (necrosis) (parenchymatous) (ulcerative)
- Tuberculosis, tubercular, tuberculous › otitis media (calcification) (calcified) (caseous) (chromogenic acid-fast bacilli) (degeneration) (fibrocaseous) (fistula) (interstitial) (isolated circumscribed lesions) (necrosis) (parenchymatous) (ulcerative)
- Otitis › media › tuberculous (acute)
- Otitis › media › in › tuberculosis (acute)
H66.3
Other chronic suppurative otitis media
Not billable
- Chapter 8
- Diseases of the ear and mastoid process
- Section
- H65-H75
Use when the record says
- Chronic suppurative otitis media NOS
Indexed under
- Otitis › media › suppurative › chronic (acute)
These two codes sit in different chapters of the Tabular List, which is usually the clearest signal that they describe different underlying processes rather than different degrees of the same one.
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