H75.01Mastoiditis in infectious and parasitic diseases classified elsewhere, right ear

H75.01 is the ICD-10-CM diagnosis code for mastoiditis in infectious and parasitic diseases classified elsewhere, right ear. It belongs to category H75 (other disorders of middle ear and mastoid in diseases classified elsewhere), block H65-H75 (diseases of middle ear and mastoid) and chapter 8 (diseases of the ear and mastoid process). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within H75.0 (mastoiditis in infectious and parasitic diseases classified elsewhere), H75.01 is specifically for mastoiditis in infectious and parasitic diseases classified elsewhere, right ear. Related codes cover unspecified ear (H75.00), left ear (H75.02) and bilateral (H75.03).

Code first: underlying disease.

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 154 (Other Ear, Nose, Mouth and Throat Diagnoses with MCC, relative weight 1.5921), DRG 155 (Other Ear, Nose, Mouth and Throat Diagnoses with CC, relative weight 0.9322) and DRG 156 (Other Ear, Nose, Mouth and Throat Diagnoses without CC/MCC, relative weight 0.6659), in MDC 03 (Diseases and Disorders of the Ear, Nose, Mouth and Throat), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It is a manifestation code, so it describes the effect of an underlying disease and can't be the principal diagnosis. Code the underlying condition first.

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

Before ICD-10, this condition was coded in ICD-9-CM as 383.89 (other disorders of mastoid).