H70.8Other mastoiditis and related conditions

H70.8 is the ICD-10-CM diagnosis code for other mastoiditis and related conditions. It belongs to category H70 (mastoiditis and related conditions), block H65-H75 (diseases of middle ear and mastoid) and chapter 8 (diseases of the ear and mastoid process). It is a header code, so it can't be reported by itself; one of its 2 subcodes must be used instead.

Within H70, choose H70.8 (Other mastoiditis and related conditions) only when documentation doesn't support a more specific option: acute mastoiditis (H70.0), chronic mastoiditis (H70.1), petrositis (H70.2) and unspecified mastoiditis (H70.9).

To report this condition, pick the subcode that matches the documentation: H70.81 (fistula) and H70.89 (conditions).

Don't report H70.8 together with the conditions in its Excludes1 note: preauricular sinus and cyst (Q18.1) and sinus, fistula, and cyst of branchial cleft (Q18.0).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.