What is ICD-10 code F10.921?

F10.921 is the ICD-10-CM diagnosis code for Alcohol use, unspecified with intoxication delirium. A person uses alcohol and is currently intoxicated with delirium, experiencing confusion and altered mental status. It belongs to the ICD-10-CM chapter for mental, behavioral and neurodevelopmental disorders (f01-f99). F10.921 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. F10.921 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. F10.921 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. F10.921 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 F10.921?

CMS phased in the V28 risk adjustment model over payment years 2024 (33%), 2025 (67%), and 2026 (100%), replacing V24. V28 consolidates HCC categories, removes some lower-acuity conditions, and recalibrates RAF weights across the entire model. F10.921 was a payment HCC under V24 (Drug/Alcohol Dependence) but the V28 recalibration removed it from the risk adjustment model. Both models can still appear in legacy data and in payer-specific lookback periods.

What should coders know when reporting F10.921?

Delirium must be documented as present during the intoxication episode This is a more severe presentation than uncomplicated intoxication and may require higher level of care Because F10.921 maps to a payment HCC, the documentation must also satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's risk adjustment score.

F10.921: Alcohol use, unspecified

ICD-10-CM Code View

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Code lookupF10.921Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Mental, Behavioral and Neurodevelopmental disorders (F01-F99) / Mental and behavioral disorders due to psychoactive substance use (F10-F19)

F10.921

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

Alcohol use, unspecified with intoxication delirium

A person uses alcohol and is currently intoxicated with delirium, experiencing confusion and altered mental status.

Buddy Insight

This code captures alcohol unspecified use with intoxication delirium, documenting an acute episode of alcohol intoxication in a patient with an established pattern of alcohol unspecified use.

CMS-HCC V28

Not risk-adjusted for this model/period.

RAF 0

CMS-HCC V24

Mapped

HCC 55

Drug/Alcohol Dependence

RAF 0.334

ACA/HHS

Not risk-adjusted for this model/period.

RAF 0

ESRD/PACE

Mapped

HCC 55

Drug/Alcohol Dependence

RAF 0.0

RXHCC

Not risk-adjusted for this model/period.

RAF 0

Code Trumping

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Compare selected patient codes to show trumped or trumps impact.

Code Book Path

Official

F10.9Alcohol use, unspecified

F10.92Alcohol use, unspecified with intoxication

F10.921Alcohol use, unspecified with intoxication delirium

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for F10.921 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for F10.921 in this effective period.

Related Child Codes

Official

F10.920Alcohol use, unspecified with intoxication, uncomplicated

F10.929Alcohol use, unspecified with intoxication, unspecified

Includes

Official

ICD-10-CM does not list Includes notes for F10.921 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for F10.921 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for F10.921 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for F10.921 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for F10.921 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Documentation of alcohol use — query the provider to specify abuse or dependence for more accurate coding when possible

Documentation of acute intoxication at the time of the encounter, with clinical findings (e.g., blood alcohol level, slurred speech, impaired coordination)

Documentation of delirium symptoms: acute onset of confusion, altered consciousness, disorientation, agitation, or perceptual disturbances during intoxication

Assessment and plan addressing alcohol use disorder with treatment recommendations (counseling, medication-assisted treatment, referral, etc.)

MEAT Support

HCC Buddy guidance

Documentation of alcohol use — query the provider to specify abuse or dependence for more accurate coding when possible

Documentation of acute intoxication at the time of the encounter, with clinical findings (e.g., blood alcohol level, slurred speech, impaired coordination)

Documentation of delirium symptoms: acute onset of confusion, altered consciousness, disorientation, agitation, or perceptual disturbances during intoxication

Assessment and plan addressing alcohol use disorder with treatment recommendations (counseling, medication-assisted treatment, referral, etc.)

Audit Caution

HCC Buddy guidance

Defaulting to unspecified use when the provider has documented enough detail to code abuse or dependence — query the provider for clarification

Assigning an alcohol use disorder code based solely on lab values (elevated GGT, MCV) without provider documentation of the clinical diagnosis

Coding intoxication at every encounter — intoxication codes are for episodes of acute intoxication, not for ongoing alcohol use disorder management

Not capturing alcohol use disorder at all when it is documented in the medical record — active conditions affecting care must be coded regardless of the primary reason for the visit

Common Mistakes

HCC Buddy guidance

F10.1x — Alcohol abuse; if documentation supports abuse, code abuse instead of unspecified use

F10.2x — Alcohol dependence; if documentation supports dependence, code dependence instead of unspecified use

Z72.89 — Other problems related to lifestyle (includes social drinking); use for non-problematic alcohol use without a disorder

Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.

Is F10.921 an HCC code?

Yes. F10.921 maps to Drug/Alcohol Dependence under the V24 model but is not retained in V28.

HCC Category Mapping

V24HCC 55, Drug/Alcohol Dependence

0.334

ESRDHCC 55, Drug/Alcohol Dependence

0.000

RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. 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.

MEAT Criteria for F10.921

For F10.921to 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 F10.921 during that encounter, not just copy-forwarded from a problem list.

What This Code Means

F10.921 is the ICD-10-CM diagnosis code for alcohol use, unspecified with intoxication delirium. A person uses alcohol and is currently intoxicated with delirium, experiencing confusion and altered mental status. F10.921 sits in the ICD-10-CM chapter for mental, behavioral and neurodevelopmental disorders (f01-f99), within the section covering mental and behavioral disorders due to psychoactive substance use (f10-f19).

Under the older CMS-HCC V24 model, F10.921 maps to Drug/Alcohol Dependence (HCC 55) with a community, non-dual, aged base RAF weight of 0.334. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.

Delirium must be documented as present during the intoxication episode. Because F10.921 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for F10.921 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Delirium must be documented as present during the intoxication episode
•This is a more severe presentation than uncomplicated intoxication and may require higher level of care

Clinical Significance

This code captures alcohol unspecified use with intoxication delirium, documenting an acute episode of alcohol intoxication in a patient with an established pattern of alcohol unspecified use. Intoxication delirium represents a more severe presentation with altered consciousness and cognitive disturbance requiring urgent medical attention. Accurate coding of the use level (unspecified use) and intoxication status is critical for tracking substance use severity and ensuring appropriate risk adjustment.

Documentation Requirements

✓Documentation of alcohol use — query the provider to specify abuse or dependence for more accurate coding when possible
✓Documentation of acute intoxication at the time of the encounter, with clinical findings (e.g., blood alcohol level, slurred speech, impaired coordination)
✓Documentation of delirium symptoms: acute onset of confusion, altered consciousness, disorientation, agitation, or perceptual disturbances during intoxication
✓Assessment and plan addressing alcohol use disorder with treatment recommendations (counseling, medication-assisted treatment, referral, etc.)

Commonly Confused Codes

•F10.1x: Alcohol abuse; if documentation supports abuse, code abuse instead of unspecified use
•F10.2x: Alcohol dependence; if documentation supports dependence, code dependence instead of unspecified use
•Z72.89: Other problems related to lifestyle (includes social drinking); use for non-problematic alcohol use without a disorder

Child Codes

F10.920Alcohol use, unspecified with intoxication, uncomplicated

F10.921Alcohol use, unspecified with intoxication delirium

F10.929Alcohol use, unspecified with intoxication, unspecified

Code Hierarchy

└F10.921Alcohol use, unspecified with intoxication delirium

F10.921 ICD-10-CM Code: Alcohol use, unspecified with intoxication delirium

HCC Buddy Code Card

F10.921

Is F10.921 an HCC code?

HCC Category Mapping

MEAT Criteria for F10.921

What This Code Means

Coding Tips

Clinical Significance

Documentation Requirements

Commonly Confused Codes

Child Codes

Code Hierarchy

Work F10.921 in HCC Buddy