What is ICD-10 code F91.0?

F91.0 is the ICD-10-CM diagnosis code for Conduct disorder confined to family context. A behavioral disorder in children where rule-breaking and aggressive behavior occurs primarily within the family setting, not in school or community. It belongs to the ICD-10-CM chapter for mental, behavioral and neurodevelopmental disorders (f01-f99). F91.0 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. F91.0 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. F91.0 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. F91.0 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

What is the V28 vs V24 difference for F91.0?

F91.0 does not map to a payment HCC under either the CMS-HCC V28 risk adjustment model or the older V24 model. V28 reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition. Because neither community model rewards F91.0 with a risk adjustment factor, it contributes zero to a Medicare Advantage beneficiary's V28/V24 community RAF score in either version. It does, however, map under the Part D RxHCC model (Personality Disorders, Anxiety, and Other Specified Mental Disorders), which affects the ESRD and/or Part D (RxHCC) risk scores. Coders should check whether provider documentation supports a more specific child code that does map to a community payment HCC.

What should coders know when reporting F91.0?

Confirm behavioral problems are limited to family context; if behaviors occur in multiple settings, consider F91.1 or F91.2 Document specific rule-breaking or aggressive behaviors reported by family members

2026 ICD-10-CM F91.0: Conduct disorder confined to family

ICD-10-CM Code View

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Code lookupF91.0Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Mental, Behavioral and Neurodevelopmental disorders (F01-F99) / Behavioral and emotional disorders with onset usually occurring in childhood and adolescence (F90-F98)

F91.0

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Conduct disorder confined to family context

A behavioral disorder in children where rule-breaking and aggressive behavior occurs primarily within the family setting, not in school or community.

Buddy Insight

Conduct disorder confined to the family context is characterized by persistent antisocial or aggressive behavior that occurs exclusively or primarily within the home environment.

CMS-HCC V28

N/A

—

Not risk-adjusted for this model/period.

Not mapped

CMS-HCC V24

N/A

—

Not risk-adjusted for this model/period.

Not mapped

ACA/HHS

N/A

—

Not risk-adjusted for this model/period.

Not mapped

ESRD/PACE

N/A

—

Not risk-adjusted for this model/period.

Not mapped

RXHCC

Mapped

HCC 133

Personality Disorders, Anxiet...

RAF 0.035

Code Book Path

Official

F91Conduct disorders

F91.0Conduct disorder confined to family context

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for F91.0 in this effective period.

Excludes 2

Official

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

Related Child Codes

Official

F91.1Conduct disorder, childhood-onset type

F91.2Conduct disorder, adolescent-onset type

F91.3Oppositional defiant disorder

F91.8Other conduct disorders

F91.9Conduct disorder, unspecified

Includes

Official

ICD-10-CM does not list Includes notes for F91.0 in this effective period.

Excludes 1

Official

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

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for F91.0 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for F91.0 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for F91.0 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Provider documentation of conduct disorder with behavior confined to the family context

Evidence of persistent pattern of aggression, destruction, deceit, or rule violation occurring primarily within the family

Documentation that the disruptive behavior is significantly reduced or absent outside the family setting

Assessment of family dynamics and potential contributing factors (abuse, neglect, family conflict)

MEAT Support

HCC Buddy guidance

Provider documentation of conduct disorder with behavior confined to the family context

Evidence of persistent pattern of aggression, destruction, deceit, or rule violation occurring primarily within the family

Documentation that the disruptive behavior is significantly reduced or absent outside the family setting

Assessment of family dynamics and potential contributing factors (abuse, neglect, family conflict)

Audit Caution

HCC Buddy guidance

Coding F91.0 when the conduct problems extend beyond the family context into school or community — use F91.1 or F91.2

Confusing conduct disorder with oppositional defiant disorder — conduct disorder involves more serious violations of societal norms

Not assessing for abuse/neglect as a contributing factor to family-confined aggressive behavior

Using the unspecified code F91.9 when the family-confined pattern is clearly documented

Common Mistakes

HCC Buddy guidance

F91.1 — Conduct disorder, childhood-onset type; childhood-onset type involves antisocial behavior across settings, not confined to family

F91.3 — Oppositional defiant disorder; ODD involves angry/argumentative behavior but typically less severe than conduct disorder

F91.9 — Conduct disorder, unspecified; use F91.0 when the family-confined pattern is documented

Z62.810 — Personal history of child physical abuse; abuse victimization must be differentiated from conduct disorder

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is F91.0 an HCC code?

F91.0 is not in the CMS-HCC V28 or V24 community payment model, but it does map to Personality Disorders, Anxiety, and Other Specified Mental Disorders under the Part D RxHCC model.

Code: F91.0
Description: Conduct disorder confined to family context
HCC (V28): No CMS-HCC V28 mapping
RAF: —
Billable: Yes
Payment year: 2026

HCC Category Mapping

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

0.035

Each model's RAF is its CMS base weight for that model's standard population, so weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.

Work F91.0 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for F91.0

For F91.0 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.

MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
EEvaluate: test results, medication response, or physical findings reviewed by the provider
AAssess: explicit mention in the assessment or plan with acknowledgment of status
TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed F91.0 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

F91.0 is the ICD-10-CM diagnosis code for conduct disorder confined to family context. A behavioral disorder in children where rule-breaking and aggressive behavior occurs primarily within the family setting, not in school or community. F91.0 sits in the ICD-10-CM chapter for mental, behavioral and neurodevelopmental disorders (f01-f99), within the section covering behavioral and emotional disorders with onset usually occurring in childhood and adolescence (f90-f98).

F91.0 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.

This code does not map to a CMS-HCC V28 payment category. Capture depends on documentation that supports the diagnosis; verify the HCC assignment against the current CMS mapping for the applicable payment year. Coders reviewing F91.0 should check whether additional documentation would support a more specific child code in the same hierarchy that does map to a payment HCC, capturing the correct specificity is the highest-impact RAF improvement available within accurate coding.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for F91.0 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Confirm behavioral problems are limited to family context; if behaviors occur in multiple settings, consider F91.1 or F91.2
•Document specific rule-breaking or aggressive behaviors reported by family members

Clinical Significance

Conduct disorder confined to the family context is characterized by persistent antisocial or aggressive behavior that occurs exclusively or primarily within the home environment. The disruptive behavior pattern is directed at family members but the child may function normally in school and community settings. This distinction is clinically important for targeted family-based interventions.

Documentation Requirements

✓Provider documentation of conduct disorder with behavior confined to the family context
✓Evidence of persistent pattern of aggression, destruction, deceit, or rule violation occurring primarily within the family
✓Documentation that the disruptive behavior is significantly reduced or absent outside the family setting
✓Assessment of family dynamics and potential contributing factors (abuse, neglect, family conflict)
✓Treatment plan emphasizing family-based interventions (family therapy, parent management training)

Commonly Confused Codes

•F91.1: Conduct disorder, childhood-onset type; childhood-onset type involves antisocial behavior across settings, not confined to family
•F91.3: Oppositional defiant disorder; ODD involves angry/argumentative behavior but typically less severe than conduct disorder
•F91.9: Conduct disorder, unspecified; use F91.0 when the family-confined pattern is documented
•Z62.810: Personal history of child physical abuse; abuse victimization must be differentiated from conduct disorder