ICD-10 Code F02.B18 – Dementia in other diseases classified elsewhere, moderate, with other behavioral disturbance (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code F02.B18 – Dementia in other diseases classified elsewhere, moderate, with other behavioral disturbance
What it is
This code identifies moderate dementia caused by another underlying disease, with additional behavioral disturbance. Use it when the dementia is not primary and the chart links it to a separate medical condition.
Clinical signs
Typical findings include clear cognitive decline affecting daily function, with moderate severity. Behavioral disturbance may include agitation, wandering, irritability, or other disruptive behaviors; clinical features vary, so refer to documentation.
When to use this code
Use this code when the provider documents dementia due to another disease and specifies moderate severity plus behavioral disturbance. It is appropriate when the record names the underlying condition and confirms the dementia is secondary to it.
Check documentation for the causal relationship and severity wording. If the chart does not clearly state moderate dementia with behavioral disturbance, do not assume this code.
Do not use for
Do not use this code for uncomplicated dementia, mild or severe dementia, or dementia without behavioral disturbance. Also avoid it when the record does not support an underlying disease cause.
Coding tip
Always code the underlying disease first when required, and verify that the provider explicitly documents both moderate severity and behavioral disturbance.