What is ICD-10 code F31.1?

F31.1 is the ICD-10-CM category for Bipolar I Disorder, Current Episode Manic Without Psychotic Features. It is not billable on its own; claims use F31.10 to F31.13, which add severity. It is used when a client with established Bipolar I has a current manic episode meeting DSM-5-TR criteria but without psychotic features (delusions, hallucinations).

What are the diagnostic criteria for F31.1?

Bipolar I Disorder requires at least one lifetime manic episode: a distinct period of abnormally and persistently elevated, expansive, or irritable mood with increased goal-directed activity or energy lasting ≥1 week (or any duration if hospitalization is required), with three or more (four if mood is only irritable) of: inflated self-esteem, decreased need for sleep, pressured speech, flight of ideas, distractibility, increased goal-directed activity, or excessive risk-taking. F31.1 specifies the current episode is manic without psychotic features.

What scale is used to screen for F31.1?

The Mood Disorder Questionnaire (MDQ) is the most widely-used screener for bipolar spectrum disorders. A positive screen requires endorsement of 7+ of 13 items, simultaneous symptom occurrence, and moderate-to-severe functional impact. MDQ has 73% sensitivity and 90% specificity for bipolar I. A positive screen warrants a full clinical evaluation.

What is the difference between Bipolar I and Bipolar II?

Bipolar I (F31.x) requires at least one lifetime manic episode. Bipolar II (F31.81) requires at least one hypomanic episode plus at least one major depressive episode, with no history of full mania. The two disorders have different treatment implications and prognoses despite similar depressive presentations.

Why screen for bipolar before treating depression?

Antidepressant monotherapy in unrecognized Bipolar I/II carries a meaningful risk of induced mania or rapid cycling. Routine MDQ screening before initiating antidepressants for any depression presentation is consistent with current clinical guidelines and reduces risk of treatment-emergent affective switches.

What are the symptoms of a manic episode?

A manic episode produces a distinct period of elevated, expansive, or irritable mood plus increased energy lasting at least one week. Core symptoms include inflated self-esteem or grandiosity, decreased need for sleep, pressured speech, racing thoughts, distractibility, increased goal-directed activity, and excessive risk-taking such as reckless spending or sexual behavior. Symptoms cause marked impairment in work or relationships and may require hospitalization.

How is bipolar I disorder diagnosed?

Bipolar I Disorder is diagnosed by a clinician using DSM-5-TR criteria, which require at least one lifetime manic episode lasting at least seven days (or any duration if hospitalization is required). Diagnosis typically follows a positive MDQ screen, structured clinical interview, collateral history from family, and review of mood, sleep, and treatment history. Many patients first present in a depressive episode and need careful screening for past mania.

What causes bipolar I disorder?

Bipolar I Disorder arises from a combination of genetic, neurobiological, and environmental factors. Heritability estimates from twin studies range from 60% to 85%, the highest of any major psychiatric condition. Neurobiological contributors include altered dopamine, serotonin, and glutamate signaling and circadian rhythm disruption. Environmental triggers include sleep loss, major life stressors, substance use, and (in vulnerable individuals) antidepressant exposure.

Can bipolar I disorder be cured?

Bipolar I Disorder is a chronic, lifelong condition managed with sustained treatment rather than cured. Mood stabilizers (lithium, valproate, lamotrigine), atypical antipsychotics, and structured psychotherapy (CBT, IPSRT, family-focused therapy) reduce episode frequency and severity. With consistent maintenance treatment, many individuals achieve long stretches of stable mood; lithium reduces suicide risk by 60% to 80% in long-term studies.

F31.1ICD-10-CMBipolar I Disorder, Current Episode Manic Without Psychotic Features

Official ICD-10-CM descriptor: Bipolar disorder, current episode manic without psychotic features · Category header, not billable: use a more specific code

Bipolar I Disorder presentation in which the current episode is manic, abnormally elevated, expansive, or irritable mood with increased energy lasting at least one week, without psychotic features.

Recommended screener

Validated screener
Mood Disorder Questionnaire (MDQ)
View scale

DSM-5-TR diagnostic criteria summary

Bipolar I Disorder requires at least one manic episode in lifetime. A manic episode requires:

A distinct period of abnormally and persistently elevated, expansive, or irritable mood AND abnormally and persistently increased goal-directed activity or energy, lasting at least 1 week (or any duration if hospitalization is required) and present most of the day, nearly every day.
Three or more of the following (four if mood is only irritable):
- Inflated self-esteem or grandiosity
- Decreased need for sleep
- More talkative than usual or pressure to keep talking
- Flight of ideas or subjective racing thoughts
- Distractibility
- Increase in goal-directed activity or psychomotor agitation
- Excessive involvement in activities with high potential for painful consequences
Marked impairment in social or occupational functioning, or hospitalization, or psychotic features.
Not attributable to a substance or another medical condition. (Antidepressant-induced mania that persists beyond physiological effect counts.)

The fourth-character subcategories specify current state: F31.0 hypomanic, F31.1 manic without psychotic features (billed as F31.10 unspecified, F31.11 mild, F31.12 moderate, or F31.13 severe), F31.2 manic with psychotic features, F31.3 mild-to-moderate depressed, F31.4 severe depressed without psychotic features, F31.5 severe depressed with psychotic features, F31.81 Bipolar II, F31.9 unspecified.

Source: American Psychiatric Association. (2022). Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR), p. 139–157.

Differential diagnosis

Bipolar II Disorder (F31.81), hypomanic episodes (≥4 days, less impairment) without ever meeting full mania criteria.
Major Depressive Disorder (F33, F32), distinguishing factor is presence/absence of any lifetime manic or hypomanic episode.
Substance/Medication-Induced Bipolar (F19.x), stimulants, corticosteroids; antidepressant-induced mania persisting beyond pharmacologic effect remains coded as bipolar.
Bipolar Disorder Due to Another Medical Condition (F06.3x), hyperthyroidism, multiple sclerosis, traumatic brain injury, cerebrovascular disease.
ADHD (F90.x), chronic, non-episodic; manic-like distractibility and motor restlessness can confuse, especially in pediatric presentations.
Borderline Personality Disorder (F60.3), affective instability is brief (hours-to-days) and reactive, vs episodic with sustained mood elevation.

Common comorbidities

Bipolar I has very high lifetime comorbidity. Common co-occurring conditions: Generalized Anxiety Disorder (F41.1), Panic Disorder (F41.0), Substance Use Disorders (F10–F19, especially alcohol), Attention-Deficit/Hyperactivity Disorder (F90.x), Eating Disorders (F50.x). Co-administer PHQ-9, GAD-7, AUDIT, and (where indicated) ASRS alongside the MDQ.

Sources

American Psychiatric Association. (2022). Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR), F31.1, p. 139–157.
Hirschfeld, R. M., et al. (2000). Development and validation of the Mood Disorder Questionnaire. American Journal of Psychiatry, 157(11), 1873–1875.
Centers for Disease Control and Prevention. ICD-10-CM Official Coding Guidelines.

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Frequently asked questions

What is ICD-10 code F31.1?
F31.1 is the ICD-10-CM category for Bipolar I Disorder, Current Episode Manic Without Psychotic Features. It is not billable on its own; claims use F31.10 to F31.13, which add severity. It is used when a client with established Bipolar I has a current manic episode meeting DSM-5-TR criteria but without psychotic features (delusions, hallucinations).
What are the diagnostic criteria for F31.1?
Bipolar I Disorder requires at least one lifetime manic episode: a distinct period of abnormally and persistently elevated, expansive, or irritable mood with increased goal-directed activity or energy lasting ≥1 week (or any duration if hospitalization is required), with three or more (four if mood is only irritable) of: inflated self-esteem, decreased need for sleep, pressured speech, flight of ideas, distractibility, increased goal-directed activity, or excessive risk-taking. F31.1 specifies the current episode is manic without psychotic features.
What scale is used to screen for F31.1?
The Mood Disorder Questionnaire (MDQ) is the most widely-used screener for bipolar spectrum disorders. A positive screen requires endorsement of 7+ of 13 items, simultaneous symptom occurrence, and moderate-to-severe functional impact. MDQ has 73% sensitivity and 90% specificity for bipolar I. A positive screen warrants a full clinical evaluation.
What is the difference between Bipolar I and Bipolar II?
Bipolar I (F31.x) requires at least one lifetime manic episode. Bipolar II (F31.81) requires at least one hypomanic episode plus at least one major depressive episode, with no history of full mania. The two disorders have different treatment implications and prognoses despite similar depressive presentations.
Why screen for bipolar before treating depression?
Antidepressant monotherapy in unrecognized Bipolar I/II carries a meaningful risk of induced mania or rapid cycling. Routine MDQ screening before initiating antidepressants for any depression presentation is consistent with current clinical guidelines and reduces risk of treatment-emergent affective switches.
Is F31.1 a billable ICD-10-CM code?
No. In the FY2027 ICD-10-CM code set (effective October 1, 2026), F31.1 is a category header, not a billable code. Claims need a 5-character code that adds severity: F31.10 (Bipolar disorder, current episode manic without psychotic features, unspecified), F31.11 (mild), F31.12 (moderate), or F31.13 (severe). Document the current severity in the chart so the right fifth character can be selected.
What are the symptoms of a manic episode?
A manic episode produces a distinct period of elevated, expansive, or irritable mood plus increased energy lasting at least one week. Core symptoms include inflated self-esteem or grandiosity, decreased need for sleep, pressured speech, racing thoughts, distractibility, increased goal-directed activity, and excessive risk-taking such as reckless spending or sexual behavior. Symptoms cause marked impairment in work or relationships and may require hospitalization.
How is bipolar I disorder diagnosed?
Bipolar I Disorder is diagnosed by a clinician using DSM-5-TR criteria, which require at least one lifetime manic episode lasting at least seven days (or any duration if hospitalization is required). Diagnosis typically follows a positive MDQ screen, structured clinical interview, collateral history from family, and review of mood, sleep, and treatment history. Many patients first present in a depressive episode and need careful screening for past mania.
What causes bipolar I disorder?
Bipolar I Disorder arises from a combination of genetic, neurobiological, and environmental factors. Heritability estimates from twin studies range from 60% to 85%, the highest of any major psychiatric condition. Neurobiological contributors include altered dopamine, serotonin, and glutamate signaling and circadian rhythm disruption. Environmental triggers include sleep loss, major life stressors, substance use, and (in vulnerable individuals) antidepressant exposure.
Can bipolar I disorder be cured?
Bipolar I Disorder is a chronic, lifelong condition managed with sustained treatment rather than cured. Mood stabilizers (lithium, valproate, lamotrigine), atypical antipsychotics, and structured psychotherapy (CBT, IPSRT, family-focused therapy) reduce episode frequency and severity. With consistent maintenance treatment, many individuals achieve long stretches of stable mood; lithium reduces suicide risk by 60% to 80% in long-term studies.