Bipolar disorder ICD-10 codes under F31 are among the most specific in the DSM-to-ICD mapping. Getting the right subcode requires knowing the current episode type and severity — and correct specificity helps avoid claim denials.
F31 Code Breakdown: Bipolar I Disorder
Bipolar I codes capture the current episode and its severity:
- F31.0 — Bipolar I, current episode hypomanic
- F31.10 — Bipolar I, current episode manic, without psychotic features, unspecified severity
- F31.11 — Current episode manic, mild
- F31.12 — Current episode manic, moderate
- F31.13 — Current episode manic, severe, without psychotic features
- F31.2 — Current episode manic with psychotic features
- F31.30 — Current episode depressed, unspecified severity
- F31.31 — Current episode depressed, mild
- F31.32 — Current episode depressed, moderate
- F31.4 — Current episode depressed, severe, without psychotic features
- F31.5 — Current episode depressed, with psychotic features
- F31.60 — Current episode mixed, unspecified severity
- F31.9 — Bipolar disorder, unspecified
Bipolar II and Related Codes
- F31.81 — Bipolar II Disorder. This is the most frequently billed bipolar code for outpatient therapy. Bipolar II is defined by at least one hypomanic episode and at least one major depressive episode, without full manic episodes.
- F34.0 — Cyclothymic Disorder. Chronic fluctuating mood with hypomanic and depressive symptoms that do not meet full criteria for hypomania or MDD.
- F31.89 — Other specified bipolar and related disorder
Most Commonly Billed Codes in Outpatient Therapy
In outpatient individual therapy settings, the most common bipolar-related billing codes are:
- F31.81 (Bipolar II) — Most frequent; clients present primarily with depression punctuated by hypomanic episodes
- F31.9 (Unspecified) — Use at intake when the full picture is not yet clear; update to a specific code once the pattern is established
- F31.32 (Bipolar I, current episode depressed, moderate) — Use when the client is in the depressive phase and depression is the active focus of treatment
Why Specificity Matters for Billing
More specific codes reduce the likelihood of a medical necessity review or denial:
- F31.9 (unspecified) may trigger a request for additional documentation from some payers because it signals an incomplete diagnostic picture
- The most specific available code that accurately represents the clinical picture should be used — but do not guess at severity if you are uncertain
- Severity coding (mild/moderate/severe) should be based on documented functional impairment and symptom count
Collaborative Care with Psychiatry
Clients with bipolar disorder are frequently co-managed by a therapist and psychiatrist. Billing considerations:
- Both providers bill their own services separately — there is no "split billing" arrangement required
- Your superbill covers psychotherapy (90837 etc.); the psychiatrist bills medication management separately
- Both can use the same F31.x diagnosis code — consistent diagnosis documentation across providers strengthens the medical necessity record
- Communication between providers (coordination of care) can be documented but is not separately billable in most OON superbill contexts
CPT Codes for Bipolar Therapy
- 90837 — 60-min individual psychotherapy (most common for bipolar disorder — often complex, longer sessions)
- 90834 — 45-min individual psychotherapy
- 90847 — Family therapy with client, useful when family education about bipolar disorder is a treatment component