ICD-10 Code F31 – Bipolar disorder (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code F31 – Bipolar disorder
What it is
F31 identifies bipolar disorder, a mental health condition marked by episodes of mania or hypomania and often depression. Use this code when the record documents bipolar disorder without a more specific subtype.
Clinical signs
Common findings include elevated or irritable mood, increased activity, reduced need for sleep, and impaired judgment. Clinical features vary; refer to documentation.
When to use this code
Use F31 when the clinician documents bipolar disorder and does not specify a more detailed code. It also applies when the note confirms a bipolar diagnosis but does not clearly distinguish current episode or severity. Check documentation for episode type, remission status, or psychotic features before coding more specifically.
Do not use for
Do not use F31 for depressive disorder, schizophrenia, or mood symptoms without a bipolar diagnosis. If the record is unclear, check documentation rather than assuming bipolar disorder.
Coding tip
Always code the most specific bipolar subtype documented, and verify whether the current episode and remission status are stated.