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ICD-10-CM 2027 diagnosis code

F31.9Bipolar disorder, unspecified

✓ Billable / specific

F31.9 is a valid, billable ICD-10-CM code for bipolar disorder, unspecified. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Looking up by condition? See ICD-10 code for Bipolar disorder, ICD-10 code for Manic depression.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About F31.9

F31.9 is the ICD-10-CM diagnosis code for bipolar disorder, unspecified. It belongs to category F31 (bipolar disorder), block F30-F39 (mood [affective] disorders) and chapter 5 (mental, Behavioral and Neurodevelopmental disorders). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within F31, choose F31.9 (unspecified) only when documentation doesn't support a more specific option: current episode hypomanic (F31.0), current episode manic without psychotic features (F31.1), current episode manic severe with psychotic features (F31.2), current episode depressed, mild or moderate severity (F31.3), current episode depressed, severe, without psychotic features (F31.4), current episode depressed, severe, with psychotic features (F31.5), current episode mixed (F31.6), currently in remission (F31.7) and 1 more.

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 885 (Psychoses, relative weight 1.3901), in MDC 19 (Mental Diseases and Disorders), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 296.80 (bipolar disorder, unspecified).

Coding notes

Applicable toConditions and synonyms classified to this code
  • Manic depression

Notes that apply from higher levels

Instructions written at a parent level also apply to F31.9.

› From F31 Bipolar disorder
Includes
  • bipolar I disorder
  • bipolar type I disorder
  • manic-depressive illness
  • manic-depressive psychosis
  • manic-depressive reaction
  • seasonal bipolar disorder
Excludes1
  • bipolar disorder, single manic episode (F30.-)
  • major depressive disorder, single episode (F32.-)
  • major depressive disorder, recurrent (F33.-)
Excludes2

Broader instructions also apply from Chapter 5: Mental, Behavioral and Neurodevelopmental disorders.

Alphabetic index entries

4 entries

Terms in the official ICD-10-CM index that lead to F31.9.

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

MDC 19 · Mental Diseases and Disorders

ICD-9-CM equivalent

Converter →
  • 296.80Bipolar disorder, unspecifiedapproximate

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about F31.9

Is F31.9 billable?

Yes. F31.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can F31.9 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict F31.9 as a principal diagnosis.

Is F31.9 a CC or MCC?

No. F31.9 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does F31.9 group to?

F31.9 is used in the MS-DRG v44.0 logic for MS-DRG 885 (Psychoses). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

What is the ICD-9 code for F31.9?

The CMS General Equivalence Mappings map F31.9 to ICD-9-CM 296.80.