ICD-10-CM > H60-H95 > H65-H75 > H70 > H70.8 H70.8 Other mastoiditis and related conditions Non-Billable/Non-Specific Type 1 Excludes preauricular sinus and cyst (Q18.1)sinus, fistula, and cyst of branchial cleft (Q18.0) Codes H70.81Postauricular fistulaH70.811Postauricular fistula, right earH70.812Postauricular fistula, left earH70.813Postauricular fistula, bilateralH70.819Postauricular fistula, unspecified earH70.89Other mastoiditis and related conditionsH70.891Other mastoiditis and related conditions, right earH70.892Other mastoiditis and related conditions, left earH70.893Other mastoiditis and related conditions, bilateralH70.899Other mastoiditis and related conditions, unspecified ear