Oppositional defiant disorder is coded F91.3. Conduct disorder is coded by onset: F91.1 (childhood-onset), F91.2 (adolescent-onset), F91.8 (other), or F91.9 (unspecified). All sit in the F91 conduct disorders block.
Quick Reference: F91 Conduct Disorder Codes
| Code | Description | Notes |
|---|---|---|
| F91.3 | Oppositional defiant disorder | Defiance and irritability toward authority; at least 6 months |
| F91.1 | Conduct disorder, childhood-onset type | At least one symptom before age 10 |
| F91.2 | Conduct disorder, adolescent-onset type | No symptoms before age 10 |
| F91.8 | Other conduct disorders | Meets conduct disorder criteria but does not fit above |
| F91.9 | Conduct disorder, unspecified | Onset type not documented; use as placeholder |
One block, distinct diagnoses. Oppositional defiant disorder and conduct disorder both live in the F91 block, but they are separate diagnoses with different criteria. Pick the specific fourth-character code that matches the presentation rather than defaulting to the unspecified F91.9.
Oppositional Defiant Disorder (F91.3)
The short answer: the ICD-10 code for oppositional defiant disorder is F91.3.
When to use: a recurrent pattern of angry or irritable mood, argumentative or defiant behavior toward authority figures, and vindictiveness. The behavior is directed at authority figures such as parents and teachers, but it does not rise to the serious rights violations that define conduct disorder.
Documentation requirements:
- A pattern of at least four symptoms across angry or irritable mood, argumentative or defiant behavior, or vindictiveness
- Symptoms present for at least six months, exhibited during interaction with at least one individual who is not a sibling
- Clinically significant distress or impairment in social, educational, or occupational functioning
- Severity where relevant (mild, moderate, or severe, based on the number of settings in which symptoms occur)
Billing note: F91.3 is a specific, billable code. Use it whenever the presentation is defiance and irritability toward authority without the serious rights violations of conduct disorder.
Conduct Disorder (F91.x): Childhood vs Adolescent Onset
Conduct disorder is a repetitive and persistent pattern of behavior that violates the basic rights of others or major age-appropriate societal norms, such as aggression toward people or animals, destruction of property, deceitfulness or theft, and serious rule violations. In ICD-10-CM the code is driven by age of onset:
- F91.1 (childhood-onset type): at least one characteristic symptom appears before age 10. Childhood-onset conduct disorder is generally associated with more aggression and a higher risk of persistence.
- F91.2 (adolescent-onset type): no characteristic symptoms appear before age 10. Onset is in the teen years.
- F91.8 (other conduct disorders): the presentation meets conduct disorder criteria but does not fit the standard onset categories.
- F91.9 (conduct disorder, unspecified): conduct disorder is present but the onset type is not yet documented. Treat this as a placeholder and specify the onset type as soon as your assessment supports it.
Document the onset. Because the code hinges on whether symptoms appeared before age 10, record the age of onset explicitly. Defaulting to F91.9 when the history supports F91.1 or F91.2 is a specificity error that payers may flag.
ODD vs Conduct Disorder vs ADHD
These three diagnoses overlap in presentation and frequently co-occur, but they are coded distinctly. The distinction drives the code:
- Oppositional defiant disorder (F91.3): defiance, argumentativeness, and irritable or angry mood directed at authority figures, without serious violations of others' rights.
- Conduct disorder (F91.1, F91.2): a more severe pattern that violates the basic rights of others or major age-appropriate norms, including aggression, destruction of property, deceit, or theft.
- ADHD (F90.x): inattention, hyperactivity, and impulsivity that is developmentally inappropriate. The behavior reflects a regulation difficulty rather than intentional defiance or rights violations.
These conditions commonly co-occur. When more than one is genuinely present, code each of them rather than choosing one. For example, a child may carry F90.2 (ADHD, combined type) alongside F91.3 (oppositional defiant disorder), and some children with conduct disorder also meet criteria for ADHD. List the primary focus of treatment first and document how each condition is being addressed.
Co-occurrence is the rule, not the exception. ADHD and ODD in particular travel together. When both are documented, code both; there is no single combined code.
Documentation Tips
Strong documentation for F91 diagnoses should include:
Symptom pattern: the specific behaviors observed, with examples, and the settings in which they occur (home, school, community).
Duration and onset: the six-month duration for ODD, and the age of onset for conduct disorder, since onset determines whether you code F91.1 or F91.2.
Severity and impairment: the concrete functional impact across settings and the severity level where a specifier applies.
Differential reasoning: a brief note on why the presentation is ODD rather than conduct disorder, or ADHD rather than intentional defiance.
Comorbidities: any co-occurring ADHD, conduct disorder, anxiety, or mood diagnoses you are also coding, with the primary focus of treatment identified.
Frequently Asked Questions
- What is the ICD-10 code for oppositional defiant disorder?
- The ICD-10-CM code for oppositional defiant disorder is F91.3. It sits within the F91 conduct disorders block and captures the pattern of angry or irritable mood, argumentative or defiant behavior toward authority figures, and vindictiveness that lasts at least six months.
- What is the code for conduct disorder?
- Conduct disorder is coded by age of onset: F91.1 for childhood-onset type, F91.2 for adolescent-onset type, or F91.9 for conduct disorder, unspecified when the onset type is not documented. F91.8 (other conduct disorders) is available for presentations that do not fit the standard onset categories.
- What is the difference between ODD and conduct disorder?
- Oppositional defiant disorder (F91.3) is defined by defiance, argumentativeness, and irritable mood directed at authority figures, without serious violations of others' rights. Conduct disorder (F91.1, F91.2) is more severe and involves a repetitive pattern of violating the basic rights of others or major age-appropriate societal norms, such as aggression, destruction of property, deceit, or theft.
- Can a child have both ADHD and ODD?
- Yes, this is very common. ADHD and ODD frequently co-occur, and when both are present you code both, for example F90.2 (ADHD, combined type) plus F91.3 (oppositional defiant disorder). Document each condition separately and identify the primary focus of treatment.
- How long must symptoms last for ODD?
- Symptoms of oppositional defiant disorder must persist for at least six months and include at least four symptoms from the categories of angry or irritable mood, argumentative or defiant behavior, or vindictiveness, exhibited during interaction with at least one individual who is not a sibling.
Accurate F91 coding comes down to matching the presentation: F91.3 for oppositional defiant disorder, and F91.1, F91.2, F91.8, or F91.9 for conduct disorder based on onset. Code ADHD and other co-occurring conditions separately when they are present.