ICD-10 Code G31.89 – Other specified degenerative diseases of nervous system (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G31.89 – Other specified degenerative diseases of nervous system
What it is
G31.89 identifies a degenerative disease of the nervous system that does not fit a more specific ICD-10-CM category. Use it for documented neurodegenerative conditions when the record names a qualifying disorder but no exact code is available.
Clinical signs
Clinical features vary; refer to documentation. Degenerative nervous system disorders may include progressive cognitive, motor, or functional decline, depending on the specific condition described by the clinician.
When to use this code
Use this code when the provider documents an “other specified” degenerative nervous system disorder and the chart supports that diagnosis. It is appropriate when a more specific degenerative disease code is not available or not documented. Check documentation for the exact disorder name and any linked neurologic findings.
Do not use for
Do not use G31.89 for unspecified degenerative nervous system disease or for conditions with a more specific ICD-10-CM code. Do not assign it when the documented disorder is not degenerative.
Coding tip
Match the code to the provider’s exact wording and confirm that “other specified” is supported in the record.