ICD-10 Code G31.1 – Senile degeneration of brain, not elsewhere classified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G31.1 – Senile degeneration of brain, not elsewhere classified
What it is
G31.1 identifies senile degeneration of the brain, a nonspecific degenerative condition affecting brain function in older adults. Use it when the record documents this diagnosis and does not name a more specific neurodegenerative disorder.
Clinical signs
Clinical features vary; refer to documentation. Commonly recorded findings may include progressive cognitive decline, memory loss, and reduced ability to manage daily activities, but you should code only what the provider documents.
When to use this code
Use G31.1 when the clinician explicitly diagnoses senile degeneration of brain and provides no more specific cause or subtype. It may appear in outpatient, inpatient, or long-term care records as the final documented diagnosis. If the note instead supports dementia, Alzheimer disease, or another defined disorder, code that condition instead.
Do not use for
Do not use this code for normal aging, mild forgetfulness, or unspecified cognitive complaints without a documented diagnosis. Check documentation if the record names a specific dementia or other neurodegenerative disease.
Coding tip
Assign G31.1 only when the provider’s wording is clear and no more specific brain disorder is documented.