F16.951
BillableHallucinogen use, unspecified with hallucinogen-induced psychotic disorder with hallucinations
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is F16.951 an HCC code?
Yes. F16.951 maps to Drug/Alcohol Psychosis under the CMS-HCC V28 risk adjustment model (and Drug/Alcohol Psychosis 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 F16.951
For F16.951 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 F16.951 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
F16.951 is the ICD-10-CM diagnosis code for hallucinogen use, unspecified with hallucinogen-induced psychotic disorder with hallucinations. A person uses hallucinogenic drugs and experiences hallucinations and other psychotic symptoms caused by the hallucinogen. F16.951 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, F16.951 maps to Drug/Alcohol Psychosis (HCC 135) with a community, non-dual, aged base RAF weight of 0.000. Under the older V24 model, F16.951 mapped to the same category but with a base RAF weight of 0.434 — V28 recalibrated weights across the entire model. 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.
Document the specific hallucinations (visual, auditory, etc.) and their relationship to hallucinogen use. Because F16.951 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 F16.951 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Document the specific hallucinations (visual, auditory, etc.) and their relationship to hallucinogen use
- •This code indicates psychosis with hallucinations as the primary psychotic feature
Clinical Significance
Hallucinogen use (unspecified) with induced psychotic disorder with hallucinations captures active perceptual disturbances caused by hallucinogen use, regardless of whether the use pattern meets abuse or dependence criteria. This maps to the higher-weighted psychosis HCC and is clinically significant for psychiatric treatment planning.
Documentation Requirements
- ✓Documentation of hallucinogen use
- ✓Specific hallucination type documented (visual, auditory, tactile)
- ✓Provider statement linking hallucinations to hallucinogen use
- ✓Mental status examination documenting psychotic features
- ✓Differentiation from HPPD/flashbacks (F16.983)
- ✓Assessment of insight and danger to self/others