383 Mastoiditis and related conditions 
383.0 Acute mastoiditis 
383.00 Acute mastoiditis without complications convert 383.00 to ICD-10-CM 383.01 Subperiosteal abscess of mastoid convert 383.01 to ICD-10-CM
383.02 Acute mastoiditis with other complications convert 383.02 to ICD-10-CM 383.1 Chronic mastoiditis convert 383.1 to ICD-10-CM 383.2 Petrositis 383.20 Petrositis unspecified convert 383.20 to ICD-10-CM 383.21 Acute petrositis convert 383.21 to ICD-10-CM 383.22 Chronic petrositis convert 383.22 to ICD-10-CM 383.3 Complications following mastoidectomy 383.30 Postmastoidectomy complication unspecified convert 383.30 to ICD-10-CM 383.31 Mucosal cyst of postmastoidectomy cavity convert 383.31 to ICD-10-CM 383.32 Recurrent cholesteatoma of postmastoidectomy cavity convert 383.32 to ICD-10-CM 383.33 Granulations of postmastoidectomy cavity convert 383.33 to ICD-10-CM 383.8 Other disorders of mastoid 383.81 Postauricular fistula convert 383.81 to ICD-10-CM 383.89 Other disorders of mastoid convert 383.89 to ICD-10-CM 383.9 Unspecified mastoiditis convert 383.9 to ICD-10-CM