F91.9

Billable

Conduct disorder, unspecified

HCC Category Mapping

RxHCCHCC 133 — Personality Disorders, Anxiety, and Other Specified Mental Disorders

0.000

What This Code Means

A behavioral disorder in children characterized by persistent patterns of violating others' rights, breaking rules, and engaging in aggressive or destructive behavior, without a more specific diagnosis identified.

Coding Tips

•Use this code only when the conduct disorder cannot be classified as childhood-onset, adolescent-onset, or unspecified onset type
•Document the specific behaviors and age of onset to support medical necessity and consider if a more specific F91 code applies

Clinical Significance

Unspecified conduct disorder is used when the provider documents a conduct disorder diagnosis without specifying the subtype or onset type. While clinically acceptable, subtype specification (childhood-onset vs. adolescent-onset) has important prognostic implications. Conduct disorders are associated with significant long-term risks including antisocial personality disorder, substance use disorders, and criminal behavior.

Documentation Requirements

✓Provider documentation of conduct disorder diagnosis
✓Evidence of persistent behavioral pattern violating others' rights or societal norms
✓Query opportunity — attempt to determine age of onset to specify childhood vs. adolescent-onset type
✓Functional impairment documentation
✓Treatment plan addressing the conduct disturbance

Commonly Confused Codes

F91.1 — Conduct disorder, childhood-onset type; use when onset before age 10 is documented F91.2 — Conduct disorder, adolescent-onset type; use when onset in adolescence is documented F91.3 — Oppositional defiant disorder; ODD is less severe than conduct disorder Z72.810 — Child and adolescent antisocial behavior; isolated antisocial acts do not constitute conduct disorder

Code Hierarchy

└F91Conduct disorders └F91.9Conduct disorder, unspecified

└F91.9Conduct disorder, unspecified