ICD-10-CM F31.81
ICD-10 Code F31.81: Bipolar II disorder
F31.81 is the ICD-10-CM code for bipolar II disorder. DSM-5-TR uses the same code regardless of current episode or specifiers.
- Official description
- Bipolar II disorder
- Billable
- Yes
- Parent category
- F31.8 · Other bipolar disorders
- DSM-5-TR name
- Bipolar II disorder
Verified against the FY2027 ICD-10-CM code set (CDC/NCHS and CMS), effective October 1, 2026 - September 30, 2027, on . Chapter 5: Mental, Behavioral and Neurodevelopmental disorders (F01-F99).
Coding notes for F31.81
- Bipolar II disorder always codes to F31.81
- Bipolar I disorder uses other F31 codes based on the current episode
- Unspecified bipolar disorder is F31.9
What to document for medical necessity
Payers look for a record that supports the diagnosis and the level of care. For bipolar and personality disorders that usually means:
- The history and current symptoms that support the diagnosis
- Current mood state or the patterns the treatment targets
- Risk assessment and safety planning, revisited when risk changes
- Coordination with prescribers and other providers
- Treatment plan goals tied to the symptoms being treated in therapy
CPT codes often billed with F31.81
The ICD-10 code says why you are treating the client and the CPT code says what you did. These are the service codes most often paired with F31.81:
Free templates for this diagnosis
Related ICD-10 codes
Frequently asked questions
What is the ICD-10 code for bipolar 2?
F31.81, Bipolar II disorder.
Does the current episode change the F31.81 code?
No. Unlike bipolar I, bipolar II disorder uses F31.81 whatever the current episode. Document the current episode and specifiers in the note.
This page is a coding reference, not clinical, diagnostic, billing, or legal advice. The diagnosis is the treating clinician's call, and payer rules vary - always confirm against the current ICD-10-CM code set and official guidelines and your payer's policy. See the full mental health ICD-10 code list.