F31.9 — Bipolar disorder, unspecified

F31.9

ICD-10 Chapter 5: Mental, Behavioral & Neurodevelopmental — illustrative image — Chapter 5: Mental, behavioral and neurodevelopmental disorders (F01–F99) — illustrative image

What this code means

Bipolar disorder causes episodes of mania (or hypomania) and depression affecting mood, energy and activity.

Also called: bipolar disorder, manic depression.

When this code is used

Used for bipolar disorder when the current episode is not specified.

Where it sits in ICD-10-CM

Code F31.9 belongs to Chapter 5: Mental, behavioral and neurodevelopmental disorders, which covers codes F01–F99 in the FY2027 ICD-10-CM tabular list. The official description above is copied verbatim from the CDC/NCHS FY2027 code file.

Related symptoms

Insomnia

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Frequently asked questions

What is ICD-10-CM code F31.9?

F31.9 is the ICD-10-CM diagnosis code for “Bipolar disorder, unspecified”. Bipolar disorder causes episodes of mania (or hypomania) and depression affecting mood, energy and activity.

When is code F31.9 used?

Used for bipolar disorder when the current episode is not specified. It belongs to Chapter 5 of ICD-10-CM (Mental, behavioral and neurodevelopmental disorders).

This guide explains ICD-10-CM codes in plain language for patients, students and other readers. It is educational information only — not coding, billing or medical advice. The code recorded for any real encounter is assigned from the full clinical documentation by the treating team and qualified coders, and only they can decide which code fits a specific case.