F19.121
BillableOther psychoactive substance abuse with intoxication delirium
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is F19.121 an HCC code?
Yes. F19.121 maps to Drug Use Disorder/Substance Use Disorder, Moderate/Severe under the CMS-HCC V28 risk adjustment model (and Drug/Alcohol Dependence under V24).
HCC Category Mapping
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 F19.121
For F19.121 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 F19.121 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
F19.121 is the ICD-10-CM diagnosis code for other psychoactive substance abuse with intoxication delirium. A person who abuses various psychoactive substances and is experiencing delirium (confusion, disorientation) due to intoxication. F19.121 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 CMS-HCC V28 risk adjustment model, F19.121 maps to Drug Use Disorder/Substance Use Disorder, Moderate/Severe (HCC 137) with a community, non-dual, aged base RAF weight of 0.358. Under the older CMS-HCC V24 model, F19.121 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 indicates a more severe presentation requiring careful documentation of mental status changes. Because F19.121 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 F19.121 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Delirium indicates a more severe presentation requiring careful documentation of mental status changes
- •Document vital signs and level of consciousness to support the delirium diagnosis
Clinical Significance
This code identifies intoxication delirium from other psychoactive substance abuse, a severe acute presentation with altered consciousness, disorientation, and potential for dangerous behavior. Intoxication delirium often requires emergency department evaluation and potential hospitalization for medical stabilization. Capturing this code accurately reflects the elevated acuity and resource intensity of these encounters.
Documentation Requirements
- ✓Provider documentation specifying the psychoactive substance(s) involved (e.g., designer drugs, bath salts, kratom, polysubstance use)
- ✓Clinical documentation supporting substance abuse pattern (maladaptive use pattern causing clinically significant impairment) without meeting criteria for dependence
- ✓Documentation of acute intoxication state with signs and symptoms present at the time of encounter
- ✓Clinical findings supporting delirium: acute onset of confusion, fluctuating consciousness, disorientation, and cognitive disturbance temporally related to substance intoxication
- ✓Assessment and plan addressing the substance use disorder with treatment approach documented
Commonly Confused Codes
- •F19.20-F19.29 (Other psychoactive substance dependence) — dependence indicates a more severe pattern with tolerance, compulsive use, or withdrawal; abuse is a less severe use pattern
- •F19.90-F19.99 (Other psychoactive substance use, unspecified) — unspecified use is used when abuse vs. dependence is not documented
- •F19.120 (Intoxication, uncomplicated) — uncomplicated intoxication lacks the delirium features of acute confusion and altered consciousness
- •F19.122 (Intoxication with perceptual disturbance) — perceptual disturbance involves hallucinations with intact reality testing, not the global cognitive disruption of delirium
- •F10-F16 (Specific substance codes: alcohol, opioids, cannabis, sedatives, cocaine, stimulants) — use substance-specific codes when the substance is identified; F19 is for 'other' or multiple unspecified substances