F18.951
BillableInhalant use, unspecified with inhalant-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 F18.951 an HCC code?
Yes. F18.951 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 F18.951
For F18.951 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 F18.951 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
F18.951 is the ICD-10-CM diagnosis code for inhalant use, unspecified with inhalant-induced psychotic disorder with hallucinations. This code describes a person who uses inhalants (such as glue, paint thinner, or other volatile substances) and is experiencing psychotic symptoms, specifically hallucinations (seeing or hearing things that aren't real). The 'unspecified' part means the documentation doesn't indicate whether the use is occasional or habitual. F18.951 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, F18.951 maps to Drug/Alcohol Psychosis (HCC 135) with a community, non-dual, aged base RAF weight of 0.000. Under the older V24 model, F18.951 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.
Verify that the psychotic symptoms with hallucinations are documented as directly related to inhalant use rather than a separate primary psychotic disorder. Because F18.951 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 F18.951 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Verify that the psychotic symptoms with hallucinations are documented as directly related to inhalant use rather than a separate primary psychotic disorder
- •Ensure the medical record specifies the type of inhalant being used if possible; if not documented, 'unspecified' is appropriate, but query the provider if additional detail is available
Clinical Significance
This code captures substance-induced psychotic disorder, which represents a serious psychiatric complication of inhalant use. Substance-induced psychosis significantly increases healthcare utilization, emergency department visits, and hospitalization risk, making accurate capture critical for risk adjustment. These patients require intensive psychiatric management and close monitoring for progression to chronic psychotic disorders.
Documentation Requirements
- ✓Provider documentation of inhalant use, specifying the type of inhalant when known (e.g., toluene, gasoline, aerosol propellants, nitrites)
- ✓Documentation of substance use pattern; query provider to determine if abuse or dependence criteria are met for more specific coding
- ✓Documentation of hallucinations (visual, auditory, tactile) that developed during or shortly after substance use, with the provider confirming they are substance-induced
- ✓Assessment and plan addressing the substance use disorder with treatment approach documented