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ICD-10-CM 2027 diagnosis code

F91.8Other conduct disorders

✓ Billable / specific

F91.8 is a valid, billable ICD-10-CM code for other conduct disorders. 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 Tantrum, ICD-10 code for Delinquency, ICD-10 code for Untruthfulness.

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 F91.8

F91.8 is the ICD-10-CM diagnosis code for other conduct disorders. It belongs to category F91 (conduct disorders), block F90-F98 (behavioral and emotional disorders with onset usually occurring in childhood and adolescence) 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 F91, choose F91.8 (Other conduct disorders) only when documentation doesn't support a more specific option: conduct disorder confined to family context (F91.0), conduct disorder, childhood-onset type (F91.1), conduct disorder, adolescent-onset type (F91.2), Oppositional defiant disorder (F91.3) and conduct disorder, unspecified (F91.9).

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 886 (Behavioral and Developmental Disorders, relative weight 1.8678), 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 312.10 (Undersocialized conduct disorder, unaggressive type, unspecified) and 312.89 (other conduct disorder).

Coding notes

Applicable toConditions and synonyms classified to this code
  • Other specified conduct disorder
  • Other specified disruptive disorder

Notes that apply from higher levels

Instructions written at a parent level also apply to F91.8.

› From F91 Conduct disorders
Excludes1
  • antisocial behavior (Z72.81-)
  • antisocial personality disorder (F60.2)
Excludes2
  • conduct problems associated with attention-deficit hyperactivity disorder (F90.-)
  • mood [affective] disorders (F30-F39)
  • pervasive developmental disorders (F84.-)
  • schizophrenia (F20.-)

Broader instructions also apply from F90-F98 Behavioral and emotional disorders with onset usually occurring in childhood and adolescence and Chapter 5: Mental, Behavioral and Neurodevelopmental disorders.

Alphabetic index entries

8 entries

Terms in the official ICD-10-CM index that lead to F91.8.

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 →
  • 312.10Undersocialized conduct disorder, unaggressive type, unspecifiedapproximate
  • 312.89Other conduct disorderapproximate

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 F91.8

Is F91.8 billable?

Yes. F91.8 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can F91.8 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict F91.8 as a principal diagnosis.

Is F91.8 a CC or MCC?

No. F91.8 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does F91.8 group to?

F91.8 is used in the MS-DRG v44.0 logic for MS-DRG 886 (Behavioral and Developmental Disorders). 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 F91.8?

The CMS General Equivalence Mappings map F91.8 to ICD-9-CM 312.10 and 312.89.