ICD-10 Code F03.91 – Unspecified dementia, unspecified severity, with behavioral disturbance (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code F03.91 – Unspecified dementia, unspecified severity, with behavioral disturbance
What it is
This code identifies dementia when the type and severity are not documented, but behavioral disturbance is present. Use it when the record shows dementia with disruptive or unsafe behaviors and no more specific dementia diagnosis.
Clinical signs
Behavioral disturbance may include agitation, aggression, wandering, paranoia, hallucinations, or other behavior changes linked to dementia. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider documents unspecified dementia and also notes behavioral disturbance. It fits cases where the chart does not identify a more specific dementia subtype or severity. You should code from the provider’s documented diagnosis, not from assumptions about cause.
Do not use for
Do not use this code if the dementia type is specified and a more precise code is available. Do not use it for behavioral symptoms without a documented dementia diagnosis.
Coding tip
Check the note for both dementia and behavioral disturbance; if either is missing, clarify or code only what is documented.