F91.9 – Conduct disorder, unspecified

ICD-10-CM 2027 diagnosis code · Behavioral and emotional disorders with onset usually occurring in childhood and adolescence

Billable code

ICD-10-CM code F91.9

Code: F91.9 (claims format: F919)
Description: Conduct disorder, unspecified
Billable: Yes – valid for HIPAA-covered transactions
Valid for: Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter: 5. Mental, Behavioral and Neurodevelopmental disorders (F01-F99)
Block: F90-F98 Behavioral and emotional disorders with onset usually occurring in childhood and adolescence
Parent codes: F91

Notes for F91.9

Applicable to:

Behavioral disorder NOS
Conduct disorder NOS
Disruptive behavior disorder NOS
Disruptive disorder NOS

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

F91 – Conduct disorders

Excludes1 (not coded here):

antisocial behavior (Z72.81-)
antisocial personality disorder (F60.2)

Excludes2 (not included here):

conduct problems associated with attention-deficit hyperactivity disorder (F90.-)
mood [affective] disorders (F30-F39)
pervasive developmental disorders (F84.-)
schizophrenia (F20.-)

Block F90-F98

Notes:

Codes within categories F90-F98 may be used regardless of the age of a patient. These disorders generally have onset within the childhood or adolescent years, but may continue throughout life or not be diagnosed until adulthood

Index terms for F91.9

Entries in the ICD-10-CM alphabetic index that lead to this code:

Related codes in F91

F91.0 – Conduct disorder confined to family contextBillable
F91.1 – Conduct disorder, childhood-onset typeBillable
F91.2 – Conduct disorder, adolescent-onset typeBillable
F91.3 – Oppositional defiant disorderBillable
F91.8 – Other conduct disordersBillable

Frequently asked questions

What is ICD-10 code F91.9?

F91.9 is the ICD-10-CM code for conduct disorder, unspecified, in the block F90-F98 (Behavioral and emotional disorders with onset usually occurring in childhood and adolescence).

Is F91.9 a billable code?

Yes. F91.9 is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.

What category does F91.9 belong to?

It belongs to category F91 – Conduct disorders.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.