ICD-10-CM Codes for Bipolar Disorder: A Provider Guide

A patient has an established bipolar disorder diagnosis, but the latest psychiatric note does not identify whether the current episode is manic, depressed, mixed, or in remission. That missing detail can change the ICD-10-CM code reported for the encounter.

Bipolar disorder is not represented by one universal diagnosis code. The F31 category contains multiple codes based on the clinical presentation, including episode type, severity, psychotic features, remission status, and Bipolar II disorder.

For U.S. providers, choosing the appropriate ICD-10-CM code helps keep diagnosis documentation and billing information consistent. However, a valid diagnosis code does not by itself guarantee coverage or payment.

What Is the ICD-10 Code for Bipolar Disorder?

Bipolar disorder is a mood disorder involving episodes of significant changes in mood, energy, activity, and functioning.

The main ICD-10-CM category is:

F31 – Bipolar disorder

F31 is a category rather than a complete code for most claims. More specific codes within the category describe the patient’s documented bipolar presentation.

Common examples include:

• F31.9 – Bipolar disorder, unspecified
• F31.81- Bipolar II disorder

Bipolar I disorder does not have a single ICD-10-CM code equivalent to F31.81. Instead, applicable F31 codes generally reflect the documented current or most recent episode and related characteristics.

Bipolar Disorder ICD-10-CM Codes

The appropriate code depends on how the diagnosis is documented.

ICD-10-CM code	Description
F31.0	Bipolar disorder, current episode hypomanic
F31.1-	Current episode manic without psychotic features
F31.2	Current episode manic, severe with psychotic features
F31.3	Current episode depressed, mild or moderate severity
F31.4	Current episode depressed, severe, without psychotic features
F31.5	Current episode depressed, severe, with psychotic features
F31.6-	Current episode mixed
F31.7-	Bipolar disorder in remission
F31.81	Bipolar II disorder
F31.89	Other bipolar disorder
F31.9	Bipolar disorder, unspecified

Codes ending in a dash contain additional subdivisions. For example, manic, depressive, mixed, and remission codes may further distinguish severity, psychotic features, or remission status.

Providers and coding teams should verify the complete code in the applicable ICD-10-CM Tabular List before reporting it.

How Do You Choose the Correct Bipolar Disorder Code?

Code selection begins with the diagnosis documented by the treating provider.

Depending on the diagnosis, ICD-10-CM may distinguish:

• bipolar disorder type
• current or most recent episode
• manic, hypomanic, depressed, or mixed presentation
• severity
• presence of psychotic features
• remission status

Not every encounter will contain all of these details, and not every F31 code requires all of them.

Coding staff should not independently determine whether a patient has Bipolar I, Bipolar II, or a particular episode based only on symptoms, medications, or screening results. When a necessary diagnostic distinction is unclear or conflicting, provider clarification may be appropriate.

When Should F31.9 Be Used?

F31.9 means bipolar disorder, unspecified.

It may be reported when bipolar disorder has been diagnosed, but the available documentation does not support another, more specific F31 code.

For example, documentation stating only “bipolar disorder” may support F31.9 when no type, episode, or other applicable distinction is established.

F31.9 is a complete, billable ICD-10-CM code. The broader F31 category is not a complete billable code because it contains more specific codes underneath it.

A billable code does not guarantee reimbursement. Coverage also depends on factors such as the service provided, medical necessity, plan benefits, authorization requirements, and payer policy.

Bipolar I vs. Bipolar II ICD-10-CM Coding

Bipolar II disorder has the specific code F31.81. Bipolar I disorder is represented through other F31 codes according to the documented presentation.

NIMH describes Bipolar I disorder as involving manic episodes lasting at least seven days or manic symptoms severe enough to require immediate hospital care. Bipolar II disorder involves a pattern of depressive and hypomanic episodes without the full manic episodes characteristic of Bipolar I.

This distinction is clinical and should come from the provider’s diagnosis rather than being inferred during coding. Cyclothymic disorder is classified separately under F34.0.

What Should Providers Document for Bipolar Disorder Coding?

The medical record should describe the bipolar disorder diagnosis and the clinical distinctions relevant to the selected code.

Depending on the encounter, useful documentation may include the current or most recent episode, severity, psychotic features, or remission status.

For longitudinal psychiatric care, providers should also update the diagnosis when the patient’s documented episode or remission status changes rather than automatically carrying forward an older episode-specific code.

The purpose is not to add terminology solely for coding specificity. The code should follow the diagnosis established by the treating provider.

Common Bipolar Disorder Coding Mistakes

1. Treating F31.9 as the default bipolar disorder code

Do not default to F31.9 when the provider has documented a bipolar disorder presentation that maps to another F31 code.

2. Submitting F31 as the complete diagnosis code

F31 identifies the bipolar disorder category. Because that category is subdivided, coding should continue to an applicable complete code.

3. Coding Bipolar II disorder as F31.9

When the documented diagnosis is Bipolar II disorder, F31.81 is the corresponding ICD-10-CM code.

4. Coding a suspected outpatient diagnosis as confirmed

In outpatient settings, diagnoses described as probable, suspected, questionable, “rule out,” or similar wording generally are not reported as though they were established. Instead, coding is based on the highest degree of certainty known for that encounter, such as documented symptoms or another confirmed condition.

The rules for uncertain diagnoses differ in certain inpatient settings.

5. Using the diagnosis code to choose a psychotherapy CPT code

ICD-10-CM codes describe diagnoses. CPT and HCPCS codes identify services and procedures.

A bipolar disorder diagnosis therefore does not determine whether the correct service code is a psychotherapy CPT code, psychiatric diagnostic evaluation, evaluation and management, or another service.

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Frequently Asked Questions

Can a bipolar disorder ICD-10-CM code be used with CPT 90834 or 90837?

Yes, when the diagnosis and psychotherapy service are appropriately supported. ICD-10-CM identifies the diagnosis, while CPT 90834 and 90837 describe psychotherapy services with different time requirements. The diagnosis does not determine which psychotherapy code to select.

Does F31.9 guarantee insurance coverage?

No. F31.9 is a valid diagnosis code, but coverage depends on the patient’s benefits, medical necessity, provider eligibility, service reported, authorization requirements, and payer policy.

Which diagnosis should be listed first when bipolar disorder occurs with another condition?

It depends on the reason for the encounter and applicable coding guidance. In outpatient care, the condition chiefly responsible for the services provided generally guides first-listed diagnosis selection. Other conditions affecting care may also be reported when appropriate.

Does bipolar disorder require prior authorization?

Not universally. Authorization requirements depend on the payer, plan, medication, procedure, or level of behavioral health service. Practices should verify the patient’s specific coverage requirements.

Should a bipolar disorder code change when the patient’s episode changes?

It may. When the provider documents a change in episode, severity, psychotic features, or remission status that corresponds to another F31 code, the diagnosis code may need to be updated for the encounter.

Official Sources

Centers for Medicare & Medicaid Services (CMS). ICD-10-CM FY2027 Files and Updates

CDC/National Center for Health Statistics (NCHS). ICD-10-CM Files

CMS/NCHS. ICD-10-CM Official Guidelines for Coding and Reporting, FY2027

National Institute of Mental Health (NIMH). Bipolar Disorder