ICD-10 Code F91.2 – Conduct disorder, adolescent-onset type (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code F91.2 – Conduct disorder, adolescent-onset type
What it is
F91.2 identifies conduct disorder that begins during adolescence. Use it when a pattern of persistent rule-breaking, aggression, or violation of others’ rights starts after age 10.
Clinical signs
Typical features include repeated lying, stealing, truancy, serious rule violations, aggression, or property destruction. Clinical features vary; refer to documentation.
When to use this code
Use F91.2 when the record clearly states adolescent-onset conduct disorder or shows onset after age 10 with established behavioral disturbance. Code it from the documented diagnosis, not from a single disruptive incident.
If the note only describes oppositional behavior, school problems, or suspected conduct issues, check documentation before assigning this code. Confirm the onset timing and that the clinician diagnosed conduct disorder.
Do not use for
Do not use this code for childhood-onset conduct disorder, oppositional defiant disorder, or isolated delinquent behavior without a formal diagnosis. Check documentation.
Coding tip
Verify age of onset in the chart; the adolescent-onset subtype depends on when the behavior pattern first appeared.