Bipolar disorder coding requires precision. Unlike depression—where you're mainly tracking single vs. recurrent and severity—bipolar codes must specify the current episode type: manic, hypomanic, depressed, or mixed. Getting this wrong doesn't just affect billing; it can create clinical confusion and complicate care coordination.
This guide covers the bipolar spectrum codes therapists encounter, with emphasis on the distinctions that matter most for accurate billing and documentation.
Quick Reference: Bipolar ICD-10 Codes
Bipolar I Disorder (F31.0–F31.7x)
| Code | Description |
|---|---|
| F31.0 | Bipolar I, current episode hypomanic |
| F31.10 | Bipolar I, current episode manic without psychotic features, unspecified |
| F31.11 | Bipolar I, current episode manic without psychotic features, mild |
| F31.12 | Bipolar I, current episode manic without psychotic features, moderate |
| F31.13 | Bipolar I, current episode manic without psychotic features, severe |
| F31.2 | Bipolar I, current episode manic with psychotic features |
| F31.30 | Bipolar I, current episode depressed, mild |
| F31.31 | Bipolar I, current episode depressed, moderate |
| F31.32 | Bipolar I, current episode depressed, severe without psychotic features |
| F31.4 | Bipolar I, current episode depressed with psychotic features |
Bipolar II Disorder
| Code | Description |
|---|---|
| F31.81 | Bipolar II disorder |
Other Bipolar Spectrum Codes
| Code | Description |
|---|---|
| F31.89 | Other bipolar disorder |
| F31.9 | Bipolar disorder, unspecified |
| F34.0 | Cyclothymic disorder |
Bipolar I vs. Bipolar II: The Core Distinction
Understanding this distinction is essential for accurate coding:
Bipolar I: History of at least one manic episode. May also have hypomanic or major depressive episodes, but mania is the defining feature.
Bipolar II: History of at least one hypomanic episode AND at least one major depressive episode. Has NEVER had a full manic episode.
| Feature | Mania (Bipolar I) | Hypomania (Bipolar II) |
|---|---|---|
| Duration | 7+ days (or any duration if hospitalization required) | At least 4 consecutive days |
| Severity | Severe; marked impairment | Observable change, but not severe impairment |
| Psychosis | May include psychotic features | No psychotic features (otherwise it's mania) |
| Hospitalization | Often required | Not required |
| Functioning | Marked impairment | Unequivocal change, but not markedly impaired |
Critical rule: If a client previously diagnosed with Bipolar II experiences a full manic episode, the diagnosis updates to Bipolar I. This is a one-way change—Bipolar I never "downgrades" to Bipolar II.
Episode Type: Current Presentation
For Bipolar I, coding requires identifying the current episode type:
Manic Episode
Criteria:
- Distinct period of abnormally elevated, expansive, or irritable mood AND increased goal-directed activity/energy
- Lasting at least 7 days (or any duration if hospitalization required)
- 3+ manic symptoms (4+ if mood is only irritable): grandiosity, decreased sleep need, pressured speech, racing thoughts, distractibility, increased goal-directed activity, excessive involvement in high-risk activities
- Marked impairment or hospitalization or psychotic features
Codes:
- F31.10–F31.13: Manic without psychotic features (specify severity)
- F31.2: Manic with psychotic features
Hypomanic Episode
Criteria:
- Same symptoms as mania but:
- Duration at least 4 days
- Unequivocal change in functioning observable to others
- NOT severe enough to cause marked impairment or hospitalization
- No psychotic features
Code: F31.0 (Bipolar I, current episode hypomanic)
Depressed Episode
Criteria:
- Meets criteria for major depressive episode
- History confirms bipolar disorder (prior manic or hypomanic episode)
Codes:
- F31.30–F31.32: Depressed, varying severity
- F31.4/F31.5: Depressed with psychotic features
Mixed Features
DSM-5 uses a "with mixed features" specifier rather than a separate mixed episode. In ICD-10:
- Code the predominant episode type with documentation of mixed features
- Remission codes reference "mixed" (F31.77, F31.78) for clients whose most recent episode had mixed features
Bipolar II Coding
Unlike Bipolar I, Bipolar II has a single code regardless of current episode type:
F31.81 — Bipolar II Disorder
When to use: Client has history of hypomanic episode(s) AND major depressive episode(s), but has NEVER had a full manic episode.
Documentation should specify:
- Current state (hypomanic, depressed, or in remission)
- Severity if currently depressed
- Any specifiers (anxious distress, mixed features, etc.)
Important: While there's only one code for Bipolar II, your notes should clearly indicate whether the client is currently hypomanic, depressed, or stable. This matters for treatment planning and care coordination.
Cyclothymic Disorder
F34.0 — Cyclothymic Disorder
When to use: Chronic fluctuating mood with periods of hypomanic symptoms and periods of depressive symptoms that don't meet full criteria for hypomanic or major depressive episodes.
Criteria:
- 2+ years of mood fluctuation (1 year for children/adolescents)
- Hypomanic and depressive symptoms present for at least half the time
- Never without symptoms for more than 2 months
- Never met criteria for major depressive, manic, or hypomanic episode
- Symptoms not better explained by another condition
Clinical relevance: Cyclothymia represents the "chronic, low-grade" end of the bipolar spectrum. Many clients with cyclothymia eventually develop Bipolar I or II—monitor for episode threshold crossings.
Common Coding Errors
Mistake 1: Using Depression Codes for Bipolar Depression
Wrong: F32.1 or F33.1 for a client with known bipolar disorder who's currently depressed
Right: F31.31 (Bipolar I, current episode depressed, moderate) or F31.81 (Bipolar II)
Why it matters: Depression codes (F32.x, F33.x) imply unipolar depression. Using them for bipolar clients creates confusion in the medical record, may result in inappropriate treatment recommendations, and could lead to antidepressant monotherapy without mood stabilization.
Mistake 2: Coding Bipolar When Only Depression is Confirmed
Scenario: Client presents with depression and mentions "mood swings" or "ups and downs"
Before coding bipolar, confirm:
- Has there been a distinct period meeting full mania or hypomania criteria?
- Duration: 7+ days for mania, 4+ days for hypomania
- Symptom count: 3+ manic symptoms (4+ if mood only irritable)
- Observable change in functioning
Mood variability alone doesn't equal bipolar disorder. If manic/hypomanic episodes aren't confirmed, code depression (F32.x/F33.x) and note "rule out bipolar" if clinically indicated.
Mistake 3: Not Updating Episode Type
Bipolar coding should reflect current status. If a client was coded as manic (F31.12) three months ago and is now depressed, update to a depressed episode code (F31.31). If stable, use a remission code (F31.73–F31.78).
Differential Diagnosis
Bipolar vs. Unipolar Depression
| Feature | Bipolar Depression | Unipolar Depression |
|---|---|---|
| History of mania/hypomania | Yes (required) | No |
| Family history of bipolar | Often present | Less common |
| Onset age | Often earlier (teens/20s) | Any age |
| Treatment response | Antidepressants may trigger mania | Standard antidepressant response |
Clinical tip: Always screen for manic/hypomanic history when evaluating depression. The MDQ (Mood Disorder Questionnaire) is a useful screening tool.
Bipolar vs. ADHD
Overlapping features (impulsivity, distractibility, increased activity) can cause confusion.
| Feature | Bipolar | ADHD |
|---|---|---|
| Onset | Episodic | Persistent since childhood |
| Course | Distinct episodes | Chronic, stable pattern |
| Mood | Elevated/euphoric during episodes | May have frustration, but not euphoria |
| Sleep | Decreased need during mania | May resist sleep, but not decreased need |
| Duration | Episode lasts days/weeks | Symptoms always present |
These conditions can co-occur. If both are present, code both.
Documentation Tips
Bipolar documentation should include:
Episode history: "Client has history of three manic episodes (ages 22, 27, and 31), each requiring hospitalization. Four major depressive episodes documented."
Current episode type and features: "Currently in major depressive episode beginning approximately 6 weeks ago. No current manic or hypomanic symptoms. Sleep increased to 10-12 hours, low energy, anhedonia, concentration difficulties."
Severity justification: "Moderate severity based on 6 depressive symptoms present, significant occupational impairment (missing work 2-3 days/week), intact self-care."
Treatment coordination: "Client followed by Dr. Smith for medication management (lithium, lamotrigine). Therapy addressing depression management, routine stabilization, and relapse prevention."
Billing Considerations
Episode Updates
Update episode coding as clinical status changes:
- Manic → Depressed: Change code
- Depressed → Remission: Change code
- Stable long-term: Use remission codes
Document the rationale for each change.
Therapy for Bipolar Disorder
Therapy is an evidence-based component of bipolar treatment. Medical necessity is well-established for:
- Psychoeducation about the disorder
- Mood monitoring and early warning sign identification
- Cognitive-behavioral interventions for depression
- Interpersonal and social rhythm therapy
- Family therapy
- Relapse prevention
Your notes should document how interventions target bipolar-related concerns.
Coordination with Prescribers
Most clients with bipolar disorder have a prescriber for mood stabilizers. Document:
- Who manages medication
- Current medications if known
- How therapy complements medication management
Frequently Asked Questions
- Can I diagnose bipolar disorder, or should I defer to psychiatry?
- Therapists can diagnose bipolar disorder within their scope of practice. However, given the medication management needs, coordination with psychiatry is typically essential. Some therapists prefer to document 'provisional' or 'rule out' and refer for psychiatric evaluation.
- What if the client was diagnosed with bipolar but I'm not sure it's accurate?
- Document your clinical observations and reasoning. If you believe the diagnosis may not be accurate, you might note 'history of bipolar disorder diagnosis; current presentation consistent with [your assessment]' and discuss with the client and their psychiatrist.
- How do I code if the client is between episodes?
- Use remission codes (F31.70–F31.78) specifying the most recent episode type. For example, F31.75 for partial remission, most recent episode depressed.
- Should I code Bipolar II when the client is currently hypomanic vs. depressed?
- The code is the same (F31.81) regardless of current state. Document current status in your notes: 'Bipolar II disorder; currently in major depressive episode' or 'Bipolar II disorder; currently hypomanic.'
Bipolar coding requires tracking episode history, current episode type, and severity. Update codes as episodes change, distinguish carefully between Bipolar I and II, and never use unipolar depression codes for clients with confirmed bipolar disorder.