ICD-10 Code F06.3 – Mood disorder due to known physiological condition (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code F06.3 – Mood disorder due to known physiological condition
What it is
This code identifies a mood disturbance that is caused by a documented medical or physiological condition. Use it when the mood change is a direct clinical consequence of another known condition, not a primary psychiatric disorder.
Clinical signs
Clinical features vary; refer to documentation. You may see depressed mood, elevated mood, irritability, or marked emotional lability linked to the underlying physiological condition.
When to use this code
Use F06.3 when the record clearly states a mood disorder due to a known medical condition, such as a neurologic, endocrine, or other physiological disorder. The provider should document the causal relationship. Report the underlying condition separately when instructed by coding guidelines.
Do not use for
Do not use this code for primary mood disorders, such as major depressive disorder or bipolar disorder, when no physiological cause is documented. Check documentation if the note only describes emotional symptoms without a stated medical cause.
Coding tip
Always verify that the provider links the mood disorder to the physiological condition before assigning F06.3.