ICD-10 Code H75.01 – Mastoiditis in infectious and parasitic diseases classified elsewhere, right ear (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H75.01 – Mastoiditis in infectious and parasitic diseases classified elsewhere, right ear
What it is
This code identifies mastoid inflammation or infection affecting the right ear when the underlying cause is an infectious or parasitic disease classified elsewhere. Use it when the mastoid process involvement is documented as secondary to another condition.
Clinical signs
Typical findings include ear pain, tenderness behind the ear, swelling, and signs of otitis or extension of infection. Clinical features vary; refer to documentation.
When to use this code
Use H75.01 when the record clearly states right-sided mastoiditis linked to an infectious or parasitic disease coded elsewhere. This is appropriate when the provider documents a causal systemic or local infection and specifies the right ear. Confirm that the underlying condition is coded separately.
Do not use for
Do not use this code for unspecified or left-sided mastoiditis, or when mastoid disease is not linked to an infectious or parasitic cause. Check documentation if the etiology or laterality is unclear.
Coding tip
Always code the underlying infectious or parasitic condition first, and verify laterality before assigning H75.01.