ICD-10 Code F06.31 – Mood disorder due to known physiological condition with depressive features (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code F06.31 – Mood disorder due to known physiological condition with depressive features
What it is
This code identifies a depressive mood disorder caused by an underlying medical condition. Use it when the mood symptoms are documented as secondary to a known physiological condition.
Clinical signs
Patients may show depressed mood, loss of interest, low energy, or related affective changes. Clinical features vary; refer to documentation, and confirm the medical condition causing the mood disturbance.
When to use this code
Use F06.31 when the record clearly links depressive features to a known physiological condition, such as a neurologic, endocrine, or other medical disorder. You should code the underlying condition as well when documented. If the provider does not specify the causal relationship, check documentation.
Do not use for
Do not use this code for primary depressive disorders without an identified medical cause. It is also inappropriate when documentation only says “depression” or when the mood change is unrelated to a physiological condition.
Coding tip
Verify that the provider explicitly documents the medical cause and depressive features before assigning F06.31.