ICD-10-CM Tabular Index · Chapter 5 · FY 2026 F91

Conduct disorders (F91) ICD-10-CM

The F91 code range covers conduct disorders with 7 ICD-10-CM diagnosis codes. 6 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.

✓ Built from the official CMS FY 2026 datasetEffective Oct 1, 2025 – Sep 30, 2026
7
Diagnosis Codes
6
Billable Codes
F91
Code Range
F90–F98
Parent Section

Type 1 Excludes

A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.

Type 2 Excludes

A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.

ICD-10-CM

Codes in the F91 Range 7 codes · 6 billable

7 of 7 shown
  • F91 Conduct disordersNon-billable
  • F91.0 Conduct disorder confined to family context
  • F91.1 Conduct disorder, childhood-onset type
  • F91.2 Conduct disorder, adolescent-onset type
  • F91.3 Oppositional defiant disorder
  • F91.8 Other conduct disorders
  • F91.9 Conduct disorder, unspecified

Clinical Terms in This Code Range

Definitions from the National Library of Medicine for conditions coded in the F91 range.

Bullying

Aggressive behavior by a more powerful party that results in physical harm to or emotional distress of the victim.

Conduct Disorder

A repetitive and persistent pattern of behavior in which the basic rights of others or major age-appropriate societal norms or rules are violated. These behaviors include aggressive conduct that causes or threatens physical harm to other people or animals, nonaggressive conduct that causes property loss or damage, deceitfulness or theft, and serious violations of rules. The onset is before age 18. (From DSM-IV, 1994)

Cyberbullying

Bullying that takes place over digital devices like cell phones and computers. It includes sending, posting, or sharing negative, harmful, false, or mean content about someone else. It can include sharing personal or private information about someone else causing embarrassment or humiliation. (from https://www.stopbullying.gov)

Occupational Stress

Adverse psychological and behavioral reactions caused by the pressures and demands of employers or clients or other factors, such as the physical environment of the workplace, WORKPLACE VIOLENCE; or WORKPLACE BULLYING.

Oppositional Defiant Disorder

A repetitive and persistent pattern of behavior that develops in childhood and is characterized as recurrent disobedient, overall negative or agitated mood, a quarrelsome attitude or being vengeful toward authority figures. Unlike in conduct disorder defiant behaviors in oppositional defiant disorders typically do not involve aggression, destruction, theft, or deceit. Oppositional defiant disorder, CONDUCT DISORDER and ATTENTION DEFICIT AND HYPERACTIVITY DISORDER sometimes co-occur.

Problem Behavior

Troublesome or disruptive behavioral displays.

About the F91 Code Range

ICD-10 code F91 covers a range of conduct disorders, which describe patterns of disruptive and antisocial behavior mainly diagnosed in children and adolescents. These codes are used to specify different types and contexts of conduct disorders, aiding in accurate diagnosis and treatment planning.

The section includes specific codes like F91.0 for conduct disorder confined to family context (also known as sibling jealousy), and F91.1 for childhood-onset conduct disorder, which involves aggressive or problematic behaviors starting early in life. The ICD-10 code for adolescent-onset conduct disorder (F91.2) addresses behavioral issues emerging during teenage years, often including group delinquency and truancy. Oppositional defiant disorder is classified as F91.3, covering defiant, non-compliant, or irritable behaviors. Other less common or unspecified conduct disorders fall under F91.8 and F91.9, which include a wide variety of disruptive behaviors such as bullying, vandalism, or temper tantrums. Using these codes helps clarify diagnoses for medical coders and healthcare providers seeking to identify or document conduct disorders by their unique presentations and contexts.

Questions About This Page

How many billable codes are in the F91 range?

Of the 7 codes in this range, 6 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.

What does the F91 range classify?

The range classifies conduct disorders. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.

Related References

Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.