H70.1
Header — not billableChronic mastoiditis
The ICD-10 code for chronic mastoiditis is H70.1.
H70.1 is a non-billable header code. It groups related conditions but cannot be used on its own for reimbursement — select one of the 4 more specific codes below.
Clinical notes
Excludes1 (not coded here)
An Excludes1 note is a pure exclusion: the excluded condition and this code should never be reported together, because the two conditions cannot occur at the same time (e.g. a congenital form vs. an acquired form of the same disease).
- tuberculous mastoiditis (A18.03)
Also known as
Alternate wording, synonyms, or specific conditions that fall under this code, listed to help confirm you've picked the right one.
- Caries of mastoid
- Fistula of mastoid
Documentation support
General coding-documentation guidance — not a substitute for payer-specific requirements or professional coding judgment.
- •This is a non-billable header code. Documentation must support a more specific child code before this diagnosis can be reported on a claim.
- •Confirm the excluded condition(s) listed above are not also present — Excludes1 conditions cannot be coded together with this one.
- •As a general rule, code to the highest level of specificity supported by the documentation in the medical record.