ICD-10 Code G05 – Encephalitis, myelitis and encephalomyelitis in diseases classified elsewhere (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G05 – Encephalitis, myelitis and encephalomyelitis in diseases classified elsewhere
What it is
G05 identifies inflammation of the brain, spinal cord, or both when the condition is caused by another disease classified elsewhere. Use it when the neurologic inflammation is documented as secondary to an underlying condition.
Clinical signs
Clinical features vary; refer to documentation. Typical findings may include altered mental status, focal neurologic deficits, weakness, sensory changes, or signs of spinal cord involvement, depending on the site affected.
When to use this code
Use G05 when the record states encephalitis, myelitis, or encephalomyelitis due to another classified disease, and the underlying cause is also documented. Code the underlying disease first when sequencing rules require it. If the chart does not clearly link the inflammation to another condition, check documentation.
Do not use for
Do not use this code for primary infectious encephalitis or myelitis without an “in diseases classified elsewhere” statement. Do not use it when the diagnosis is uncertain or the cause is not documented.
Coding tip
Always verify the underlying etiology and sequence the causal condition according to ICD-10-CM guidance.