ICD-10 Code F51.9 – Sleep disorder not due to a substance or known physiological condition, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code F51.9 – Sleep disorder not due to a substance or known physiological condition, unspecified
What it is
F51.9 identifies an unspecified sleep disorder that is not caused by a substance or a known medical condition. Use it when the record confirms a sleep disorder but does not specify the exact type.
Clinical signs
Clinical features vary; refer to documentation. Commonly, the chart may note persistent problems with sleep onset, sleep maintenance, or nonrestorative sleep without a documented physiologic cause.
When to use this code
Use F51.9 when the provider documents a sleep disorder but does not name insomnia, parasomnia, or another more specific diagnosis. It is also appropriate when the cause is not linked to a substance or a known physiological condition. Check documentation if the note is vague or incomplete.
Do not use for
Do not use this code for sleep problems clearly due to medications, alcohol, or another substance. Also avoid it when the record supports a specific sleep disorder or a sleep disturbance from a known medical condition.
Coding tip
If the provider gives a more specific sleep diagnosis, code that instead of F51.9.