What is ICD-10 code F31.78?

F31.78 is the ICD-10-CM diagnosis code for Bipolar disorder, in full remission, most recent episode mixed. It belongs to the ICD-10-CM chapter for mental, behavioral and neurodevelopmental disorders (f01-f99). F31.78 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. F31.78 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. F31.78 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. F31.78 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Which HCC does F31.78 map to under V28?

F31.78 has no payable CMS-HCC V28 mapping in the final FY2026 CMS file.

What RAF reference is published for F31.78?

F31.78 has no V28 reference coefficient because the final FY2026 source verifies no payable V28 mapping.

What is the V28 vs V24 difference for F31.78?

F31.78 has verified no payable V28 mapping in the final FY2026 source. Select a historical effective period before making any V24 comparison.

What documentation supports F31.78?

Use this code only when documentation clearly states the patient is in 'full remission' or 'complete remission' - partial remission requires a different code (F31.77) The 'most recent episode mixed' component is important; verify the last bipolar episode involved both manic and depressive features before assigning this specific code F31.78 is not a CMS-HCC V28 payment code in the verified current source, so MEAT is not the payment hook. Documentation still has to support the diagnosis if you report it.

Can F31.78 be a primary diagnosis?

Yes. F31.78 carries no code-first instruction in the FY2026 tabular, so it can be the first-listed diagnosis when it is the condition chiefly responsible for the encounter and the note supports it, and it can also be reported as a secondary diagnosis. For risk adjustment the order does not matter; the V28 category is the same either way.

Which codes cannot be reported with F31.78?

The Excludes1 note that applies to F31.78 lists bipolar disorder, single manic episode (F30.-); major depressive disorder, single episode (F32.-); major depressive disorder, recurrent (F33.-). An Excludes1 condition is not reported together with F31.78; report one or the other, unless the two conditions are unrelated, which the ICD-10-CM Official Guidelines (Section I.A.12.a) allow. The Excludes2 note lists symptoms, signs and abnormal clinical laboratory findings, not elsewhere classified (R00-R99); cyclothymia (F34.0); those are separate conditions that may be reported together with F31.78 when both are documented.

2026 ICD-10-CM F31.78: Bipolar disorder, in full remission

F31.78 is not a CMS-HCC payment code. MEAT criteria · RAF Calculator · HCC Buddy coding tools

ICD-10-CM Code View

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Code lookupF31.78

Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Mental, Behavioral and Neurodevelopmental disorders (F01-F99) / Mood [affective] disorders (F30-F39)

F31.78

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Bipolar disorder, in full remission, most recent episode mixed

This code describes bipolar disorder where the patient has completely recovered from their most recent mixed episode (which included both manic and depressive symptoms) and is currently experiencing no symptoms. The condition is in remission, meaning the patient is stable and symptom-free at this time.

Buddy Insight

Bipolar disorder in full remission with the most recent episode being mixed indicates complete resolution of symptoms from the last mixed mood episode.

Overview Risk Models Code Book Documentation Audit Notes Edition comparison

CMS-HCC V28

N/A

—

Not risk-adjusted for this model/period.

Not mapped

CMS-HCC V24

Historical

Not used for standard CY2026 Medicare Advantage payment. Select a historical period to review V24.

Not used for CY2026 payment

ACA/HHS

Context needed

HCC 088

Conditional HHS-HCC mapping: HCC 088 when age >= 2. Select the member context before showing a coefficient reference. Metal level and model segment are required for coefficients; no single RAF is shown.

Coefficient needs member context

ESRD/PACE

Context needed

HCC 59

ESRD candidates: HCC 59 when age >= 2 or age < 2. ESRD mapping is separate from PACE. Dialysis, graft, age, and other member context determine the applicable coefficient.

Coefficient needs member context

RXHCC

Mapped

HCC 131

Bipolar Disorders

Code-level coefficient reference

Code Book Path

Official

F31Bipolar disorder F31.7Bipolar disorder, currently in remission F31.78Bipolar disorder, in full remission, most recent episode mixed

Inclusion Terms

Official

No inclusion terms are included in this display for F31.78. Check the code and parent instructions in the Code Book.

Excludes 2

Official

symptoms, signs and abnormal clinical laboratory findings, not elsewhere classified (R00-R99)Inherited from F01-F99, F31
cyclothymia (F34.0)Inherited from F01-F99, F31

Related Codes

Official

F31.70Bipolar disorder, currently in remission, most recent episode unspecified F31.71Bipolar disorder, in partial remission, most recent episode hypomanic F31.72Bipolar disorder, in full remission, most recent episode hypomanic F31.73Bipolar disorder, in partial remission, most recent episode manic F31.74Bipolar disorder, in full remission, most recent episode manic

Includes

Official

disorders of psychological developmentInherited from F01-F99, F31
bipolar I disorderInherited from F01-F99, F31
bipolar type I disorderInherited from F01-F99, F31
manic-depressive illnessInherited from F01-F99, F31
manic-depressive psychosisInherited from F01-F99, F31
manic-depressive reactionInherited from F01-F99, F31
seasonal bipolar disorderInherited from F01-F99, F31

Excludes 1

Official

bipolar disorder, single manic episode (F30.-)Inherited from F31
major depressive disorder, single episode (F32.-)Inherited from F31
major depressive disorder, recurrent (F33.-)Inherited from F31

Code First

Official

No Code First sequencing instructions are included in this display for F31.78. Check the code and parent instructions in the Code Book.

Use Additional

Official

No Use Additional Code instructions are included in this display for F31.78. Check the code and parent instructions in the Code Book.

Code Also

Official

No Code Also instructions are included in this display for F31.78. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

Confirmed bipolar disorder diagnosis

Most recent episode identified as mixed

Full remission with complete absence of mood symptoms documented

Maintenance medication regimen

MEAT Support

HCC Buddy guidance

Confirmed bipolar disorder diagnosis

Most recent episode identified as mixed

Full remission with complete absence of mood symptoms documented

Maintenance medication regimen

Audit Caution

HCC Buddy guidance

Using full remission when any residual manic or depressive symptoms are present

Not identifying the most recent episode type correctly

Discontinuing bipolar coding during remission visits

Failing to differentiate mixed episode history from rapid cycling

Common Mistakes

HCC Buddy guidance

F31.77 — Bipolar disorder, partial remission, most recent mixed: Residual symptoms present

F31.74 — Bipolar disorder, full remission, most recent manic: Different episode type

F31.76 — Bipolar disorder, full remission, most recent depressed: Different episode type

F31.70 — Bipolar disorder, remission, unspecified: Less specific

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is F31.78 an HCC code?

F31.78 is not in the CMS-HCC V28 or V24 community payment model. F31.78 has a separate mapping under the CMS-HCC ESRD model (HCC 59 (Major Depressive/Bipolar/and Paranoid Disorders)) and the Part D RxHCC model (HCC 131 (Bipolar Disorders)); the applicable result needs member context. F31.78 also appears in the HHS-HCC commercial risk model (HCC 088 (HHS-HCC 088 adult, RAF varies by metal level)), where the result depends on member context and is not a Medicare Advantage payment mapping.

Code: F31.78
Description: Bipolar disorder, in full remission, most recent episode mixed
HCC (V28): No CMS-HCC V28 mapping
RAF reference coefficient: —
Billable: Yes
Payment year: 2026

HCC Category Mapping

RxHCCHCC 131, Bipolar Disorders

Not separately weighted

These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. Weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.

Work F31.78 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for F31.78

For F31.78, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.

MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
EEvaluate: test results, medication response, or physical findings reviewed by the provider
AAssess: explicit mention in the assessment or plan with acknowledgment of status
TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Coder workflow notes

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What This Code Means

F31.78 is the ICD-10-CM diagnosis code for bipolar disorder, in full remission, most recent episode mixed. This code describes bipolar disorder where the patient has completely recovered from their most recent mixed episode (which included both manic and depressive symptoms) and is currently experiencing no symptoms. The condition is in remission, meaning the patient is stable and symptom-free at this time. F31.78 sits in the ICD-10-CM chapter for mental, behavioral and neurodevelopmental disorders (f01-f99), within the section covering mood [affective] disorders (f30-f39).

F31.78 has no mapping under the CMS-HCC V28 or V24 community payment models. F31.78 has a separate mapping under the CMS-HCC ESRD model (HCC 59 (Major Depressive/Bipolar/and Paranoid Disorders)) and the Part D RxHCC model (HCC 131 (Bipolar Disorders)); the applicable result needs member context. F31.78 also appears in the HHS-HCC commercial risk model (HCC 088 (HHS-HCC 088 adult, RAF varies by metal level)), where the result depends on member context and is not a Medicare Advantage payment mapping. Do not assign V28 risk adjustment value from this page; verify the applicable model and payment year before using this code for risk adjustment.

Use this code only when documentation clearly states the patient is in 'full remission' or 'complete remission' - partial remission requires a different code (F31.77).

HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for F31.78 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Use this code only when documentation clearly states the patient is in 'full remission' or 'complete remission' - partial remission requires a different code (F31.77)
•The 'most recent episode mixed' component is important; verify the last bipolar episode involved both manic and depressive features before assigning this specific code

Clinical Significance

Bipolar disorder in full remission with the most recent episode being mixed indicates complete resolution of symptoms from the last mixed mood episode. Full remission from a mixed episode is a positive clinical milestone given the complexity and treatment resistance of mixed states. Continued monitoring is warranted due to the high recurrence rate.

Documentation Requirements

✓Confirmed bipolar disorder diagnosis
✓Most recent episode identified as mixed
✓Full remission with complete absence of mood symptoms documented
✓Maintenance medication regimen
✓Relapse monitoring plan

Commonly Confused Codes

•F31.77: Bipolar disorder, partial remission, most recent mixed: Residual symptoms present
•F31.74: Bipolar disorder, full remission, most recent manic: Different episode type
•F31.76: Bipolar disorder, full remission, most recent depressed: Different episode type
•F31.70: Bipolar disorder, remission, unspecified: Less specific