ICD-10 Code G37.81 – Myelin oligodendrocyte glycoprotein antibody disease (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G37.81 – Myelin oligodendrocyte glycoprotein antibody disease
What it is
G37.81 identifies myelin oligodendrocyte glycoprotein antibody disease, an inflammatory demyelinating disorder of the central nervous system. Use it when documentation confirms MOG antibody–associated disease or a related clinician diagnosis.
Clinical signs
Clinical features vary; refer to documentation. Commonly reported findings include optic neuritis, myelitis, or acute brain or brainstem inflammation, with diagnosis supported by MOG antibody positivity and compatible neurologic assessment.
When to use this code
Use this code when the provider documents MOG antibody disease, MOGAD, or a confirmed myelin oligodendrocyte glycoprotein antibody–associated demyelinating condition. It may also apply when the record clearly links the episode to this diagnosis, even if symptoms are described separately. Check documentation if the diagnosis is only suspected.
Do not use for
Do not use G37.81 for nonspecific demyelination, multiple sclerosis, or optic neuritis without documented MOG antibody disease. If the chart only says “rule out” or “possible” MOGAD, check documentation before coding.
Coding tip
Code the confirmed diagnosis from the provider’s final assessment, not the isolated antibody result alone.