ICD-10 Codes for Bipolar Disorder: F31 Code Guide

Bipolar disorder is coded in ICD-10-CM category F31. Bipolar I codes record the current episode (hypomanic, manic, depressed or mixed), its severity and psychotic features, or remission by most recent episode. Bipolar II is F31.81, unspecified bipolar disorder is F31.9, and cyclothymia is F34.0. None changed for FY2027 per CMS. In Ona, the chosen code feeds the claim.

Quick answer:

F31 includes bipolar I disorder. Its codes are built around the current episode: F31.0 hypomanic, F31.1- manic, F31.2 manic with psychotic features, F31.3- to F31.5 depressed, F31.6- mixed, F31.7- in remission.
Bipolar II has one code, F31.81, with no episode or severity characters.
A note that says "bipolar, currently manic" with no severity or psychotic status indexes to F31.9. The detail in the documentation decides how specific the claim can be.

The F31 Codes at a Glance

Every code and descriptor below comes from the FY2027 ICD-10-CM code descriptions, tabular list and index published by CMS, cross-checked on icd10data.com on October 22, 2026. FY2027 codes apply to dates of service from October 1, 2026 to September 30, 2027.

Code	Official FY2027 descriptor
F31.0	Bipolar disorder, current episode hypomanic
F31.10	Bipolar disorder, current episode manic without psychotic features, unspecified
F31.11	Bipolar disorder, current episode manic without psychotic features, mild
F31.12	Bipolar disorder, current episode manic without psychotic features, moderate
F31.13	Bipolar disorder, current episode manic without psychotic features, severe
F31.2	Bipolar disorder, current episode manic severe with psychotic features
F31.30	Bipolar disorder, current episode depressed, mild or moderate severity, unspecified
F31.31	Bipolar disorder, current episode depressed, mild
F31.32	Bipolar disorder, current episode depressed, moderate
F31.4	Bipolar disorder, current episode depressed, severe, without psychotic features
F31.5	Bipolar disorder, current episode depressed, severe, with psychotic features
F31.60	Bipolar disorder, current episode mixed, unspecified
F31.61	Bipolar disorder, current episode mixed, mild
F31.62	Bipolar disorder, current episode mixed, moderate
F31.63	Bipolar disorder, current episode mixed, severe, without psychotic features
F31.64	Bipolar disorder, current episode mixed, severe, with psychotic features
F31.70	Bipolar disorder, currently in remission, most recent episode unspecified
F31.71	Bipolar disorder, in partial remission, most recent episode hypomanic
F31.72	Bipolar disorder, in full remission, most recent episode hypomanic
F31.73	Bipolar disorder, in partial remission, most recent episode manic
F31.74	Bipolar disorder, in full remission, most recent episode manic
F31.75	Bipolar disorder, in partial remission, most recent episode depressed
F31.76	Bipolar disorder, in full remission, most recent episode depressed
F31.77	Bipolar disorder, in partial remission, most recent episode mixed
F31.78	Bipolar disorder, in full remission, most recent episode mixed
F31.81	Bipolar II disorder
F31.89	Other bipolar disorder
F31.9	Bipolar disorder, unspecified
F34.0	Cyclothymic disorder

Six F31 headings are not billable on their own: F31, F31.1, F31.3, F31.6, F31.7 and F31.8 all need another character. F31.0, F31.2, F31.4, F31.5 and F31.9 are complete at four characters. The FY2027 guidelines state that a code is invalid if it has not been coded to the full number of characters required, so a superbill that lists "F31.1" or "F31.7" as a pick will produce rejections.

How an F31 Code Is Built

Read an F31 code from left to right and it answers three questions in order.

What is the current episode? Hypomanic (F31.0), manic (F31.1- and F31.2), depressed (F31.3-, F31.4, F31.5) or mixed (F31.6-). Or, if the patient is in remission, the code moves to F31.7- and records the most recent episode instead.

How severe is it? Mild, moderate or severe, coded in the fifth character for manic without psychotic features, depressed at mild or moderate severity, and mixed. Severe depressed episodes have their own four-character codes, F31.4 and F31.5.

Are there psychotic features? For manic episodes, F31.2. For severe depressed episodes, F31.5. For severe mixed episodes, F31.64. The tabular list groups mood-congruent and mood-incongruent psychotic symptoms under the same code in each case.

Remission works differently. F31.71 to F31.78 pair partial or full remission with the most recent episode type: hypomanic, manic, depressed or mixed. F31.70 is in remission with the most recent episode not documented.

Every one of these characters is a documentation dependency. The FY2027 guidelines direct coders to the highest level of specificity supported by the medical record documentation, and they also say it is inappropriate to select a specific code the documentation does not support. Severity, psychotic status and remission all have to be in the note for the code to say them.

The Index Defaults That Push Claims to F31.9

The alphabetic index shows exactly how vague documentation becomes an unspecified claim:

"Disorder, bipolar" with nothing more goes to F31.9.
"Disorder, bipolar, current, manic" with no psychotic status or severity also goes to F31.9.
"Disorder, bipolar, current, depressed" with no further detail goes to F31.9 as well.
"Disorder, bipolar, current, mixed" goes to F31.60, and "in remission" alone goes to F31.70.

So a note that documents a current manic episode but omits whether psychotic features are present lands on the same code as a note that says only "bipolar". That is the specificity gap in this category, and it sits entirely in the documentation.

F31.9 is a billable code, and Section I.B.18 of the FY2027 guidelines says unspecified codes have "acceptable, even necessary, uses" when they reflect what is known at that encounter. The problem is not F31.9 at an initial visit. It is F31.9 on every claim for a year of medication management while the notes describe each episode in detail. Some payer policies list accepted diagnoses for particular services, and the level of scrutiny unspecified codes draw differs between payers.

Bipolar II: F31.81

Bipolar II disorder has a single code, F31.81, with "bipolar disorder, type 2" as its inclusion term. Unlike bipolar I, there are no further characters for the current episode, severity or remission. The episode detail still belongs in the clinician's note, but the code does not carry it.

That makes F31.81 one of the easiest codes in the family to get right, provided the note says bipolar II. Documentation that only says "bipolar disorder" indexes to F31.9 and cannot be coded to F31.81 by inference.

Bipolar I, F31.89 and F31.9

The F31 category's includes note lists bipolar I disorder, bipolar type I disorder, manic-depressive illness, manic-depressive psychosis, manic-depressive reaction and seasonal bipolar disorder. There is no code titled "bipolar I"; bipolar I is the default sense of the whole category, expressed through the episode-based codes above.

F31.89, other bipolar disorder, carries the inclusion term "recurrent manic episodes NOS". F31.9, bipolar disorder, unspecified, carries "manic depression".

Neighbors and Excludes Notes

The F31 category sits beside several codes that clinicians and billers mix up with it.

F30.-, manic episode. F31 has an Excludes1 for bipolar disorder, single manic episode, which the index sends to F30. The FY2027 guidelines define Excludes1 as "NOT CODED HERE!", two codes never reported together.
F32.- and F33.-, major depressive disorder. F31 carries Excludes1 notes for both, and both depression categories carry an Excludes1 for bipolar disorder in return. When a diagnosis moves from depression to bipolar disorder, the depression code comes off.
F34.0, cyclothymic disorder. Listed under F31 as an Excludes2, which the guidelines describe as a condition that is not part of the code above it but may coexist. Its inclusion terms include cyclothymia and cyclothymic personality.
F06.33 and F06.34. Mood disorder due to known physiological condition with manic features or with mixed features. These sit in F01-F09, for conditions due to known physiological causes.
F39, unspecified mood [affective] disorder. The index sends "disorder, mood" with no further detail here, not to F31.

What Changed for FY2027

Nothing in F31, F30 or F34. The CMS FY2027 tabular addendum touches chapter 5 only with a note change at F02 and a new code, F64.A, gender identity disorder, in remission. Bipolar codes and descriptors carry over unchanged, so templates and favorites lists built for last year remain valid. To look a code up yourself, the CDC's ICD-10-CM page links to the NCHS code browser.

Documentation Checklist for Bipolar Claims

None of this is clinical guidance. It is the billing team's checklist for whether the note can carry the code on the claim.

Episode type, every visit. Hypomanic, manic, depressed, mixed, or in remission with the most recent episode named.
Severity, where the code asks for it. Mild, moderate or severe.
Psychotic features, stated either way. Without it, a severe manic episode cannot be coded past F31.9.
Bipolar II named as bipolar II. It cannot be inferred.
No uncertain diagnoses on outpatient claims. Section IV.H says not to code diagnoses documented as "probable", "suspected", "rule out" or "working diagnosis".
A diagnosis pointer on every service line. Especially on visits that combine an E/M service with psychotherapy.

Because the current episode changes, a bipolar code is more likely than most to go stale. The code that was right in March can be wrong in June, and the claim should follow the note.

How the Code Moves From Chart to Claim in Ona

Ona is an AI-native, all-in-one practice management platform, with CRM, EHR and RCM on one patient record. Behavioral health practices, from solo psychiatric prescribers to multi-location groups with in-house billers, use the same record from the session note to the paid claim.

Choosing the code. Add diagnosis searches by condition name or ICD-10 code and narrows level by level, so F31 opens into F31.7 and then into F31.75 rather than stopping at a heading. Each row is labeled billable or not billable, and Ona's diagnoses help page states that a non-billable code cannot be added from the coded picker. Severity, onset and certainty can be recorded on the diagnosis too; Section IV.H still decides whether a provisional diagnosis belongs on the claim.

Updating it as the episode changes. A saved diagnosis code cannot be edited in Ona. When the current episode changes, archive the old record and add the new code, so the chart shows which code applied at which visit.

The note. AI charting drafts against your templates from the recording, intake and chart, and each change Ona proposes waits for the clinician to keep or discard it. Signed notes lock, and corrections become amendments with a required reason.

The claim. Per Ona Insurance, each insured visit's draft claim rebuilds as diagnoses, procedures and services change. The "Diagnosis codes on every line" billing rule requires a linked diagnosis on every claim line, and blocking errors stop submission until fixed. Eligibility is checked at booking and again in the 48 hours before the visit.

After submission. Claims go out through Ona Clearing House or a connected Claim.MD account. Ona separates clearinghouse rejections from payer denials, and denied claims can be corrected as a linked replacement and resubmitted. From visit billing to superbill and claim covers each step, including superbills for out-of-network patients. Prescribers who also send prescriptions from the chart can read the best EHR for psychiatry and prescribing practices.

What It Costs

Diagnosis coding, charting and claims are part of the seat. Per Ona's pricing page, a practitioner seat is $130 per month and a staff seat $45, with 10% off annually and a 14-day free trial with no credit card. E-prescribing is $45 per prescribing practitioner, with EPCS a further $25. Insurance billing adds an Ona Clearing House plan from $69 to $1,099 per month, with unlimited providers and payer enrollments included. Practices with five or more practitioners or several locations get custom pricing.

This coding guidance is general and reflects the FY2027 code set per CMS; payer rules vary, so confirm specific requirements with the payer.

Frequently asked questions

What is the ICD-10 code for bipolar disorder?

Bipolar disorder is coded in category F31. The specific code depends on the current episode, its severity and psychotic features, or remission by most recent episode. F31.9 is bipolar disorder, unspecified, and F31.81 is bipolar II disorder.

What is the ICD-10 code for bipolar 1 disorder?

There is no single bipolar I code. The F31 category includes bipolar I disorder, and the code is chosen by current episode: F31.0 hypomanic, F31.10 to F31.13 or F31.2 manic, F31.30 to F31.5 depressed, F31.60 to F31.64 mixed, or F31.70 to F31.78 in remission.

What is the ICD-10 code for bipolar 2 disorder?

F31.81, bipolar II disorder. Its inclusion term is bipolar disorder, type 2. It has no further characters for episode, severity or remission, so the code is complete at five characters.

Why does my bipolar claim keep defaulting to F31.9?

Because the documentation does not support more. The FY2027 index sends bipolar disorder with a current manic or depressed episode but no severity or psychotic status to F31.9. Stating episode type, severity and psychotic features in the note supports a specific code.

What is the ICD-10 code for cyclothymia?

F34.0, cyclothymic disorder, with cyclothymia as an inclusion term. It sits in F34, persistent mood disorders, and F31 lists it as an Excludes2.

Did the bipolar ICD-10 codes change for FY2027?

No. The CMS FY2027 tabular addendum changes chapter 5 only with a note under F02 and a new code, F64.A. The F31 codes and descriptors are unchanged.

Next step

Bring a medication management visit for a bipolar patient to a 15-minute demo and follow the episode-specific code from the diagnosis picker to the draft claim. Or start the 14-day free trial from the pricing page, no credit card needed.