ICD-10 Code F03.A18 – Unspecified dementia, mild, with other behavioral disturbance (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code F03.A18 – Unspecified dementia, mild, with other behavioral disturbance
What it is
This code identifies mild dementia when the type is not specified and the patient also has another behavioral disturbance. Use it when documentation confirms dementia but does not name a specific cause.
Clinical signs
Typical findings include mild cognitive decline affecting daily function, plus a documented behavioral change such as agitation, irritability, or similar disturbance. Clinical features vary; refer to documentation.
When to use this code
Use F03.A18 when the provider documents unspecified dementia and notes a behavioral disturbance, but does not identify the dementia subtype. It fits cases where the record supports mild severity and the behavior is part of the diagnosis. If the chart gives a specific dementia type, code that instead.
Do not use for
Do not use this code for dementia without behavioral disturbance or when the dementia type is specified. Check documentation if the behavior is not clearly linked to the dementia.
Coding tip
Confirm both mild severity and the presence of a behavioral disturbance before assigning F03.A18.