ICD-10 Code F51.8 – Other sleep disorders not due to a substance or known physiological condition (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code F51.8 – Other sleep disorders not due to a substance or known physiological condition
What it is
F51.8 is used for sleep disorders that do not fit a more specific insomnia, parasomnia, or other defined sleep diagnosis and are not caused by substances or a known medical condition.
Clinical signs
Clinical features vary; refer to documentation. You may see persistent sleep complaints, abnormal sleep behavior, or disrupted sleep that does not meet criteria for a more specific sleep disorder.
When to use this code
Use this code when the provider documents an unspecified or other sleep disorder and rules out substance use or an underlying physiological cause. It is appropriate when the record describes a sleep problem but does not support a more specific ICD-10-CM sleep code. Check documentation for the exact sleep complaint and any excluded causes.
Do not use for
Do not use F51.8 for sleep disorders clearly linked to medications, alcohol, or a medical condition. Also avoid it when the documentation supports a more specific insomnia, parasomnia, or other defined sleep diagnosis.
Coding tip
Before assigning F51.8, confirm the provider has documented that the sleep disorder is not due to a substance or known physiological condition.