ICD-10 Code F51.05 – Insomnia due to other mental disorder (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code F51.05 – Insomnia due to other mental disorder
What it is
Use this code for insomnia that is linked to another mental disorder, such as when sleep difficulty is part of the psychiatric condition. The insomnia is not coded as a standalone primary sleep disorder.
Clinical signs
Typical features include trouble falling asleep, staying asleep, or waking too early, with associated sleep dissatisfaction or daytime impairment. Clinical features vary; refer to documentation.
When to use this code
Use F51.05 when the record clearly states insomnia is due to, or associated with, another mental disorder. You should code the documented mental disorder separately when instructed by the record and coding guidelines. If the cause is unclear, check documentation.
Do not use for
Do not use this code for insomnia caused by a medical condition, substance, or medication effect. It is also not the best choice for nonspecific sleep complaints without documented linkage to a mental disorder.
Coding tip
Confirm the chart links the insomnia to a mental disorder before assigning F51.05.