F18.97
BillableInhalant use, unspecified with inhalant-induced persisting dementia
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is F18.97 an HCC code?
Yes. F18.97 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 F18.97
For F18.97 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 F18.97 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
F18.97 is the ICD-10-CM diagnosis code for inhalant use, unspecified with inhalant-induced persisting dementia. A person with inhalant use (not dependent) who has developed long-term dementia (permanent memory loss and cognitive decline) from their inhalant exposure. F18.97 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, F18.97 maps to Drug/Alcohol Psychosis (HCC 135) with a community, non-dual, aged base RAF weight of 0.000. Under the older V24 model, F18.97 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 that dementia is persistent and caused by inhalant use, not temporary intoxication. Because F18.97 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 F18.97 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Document that dementia is persistent and caused by inhalant use, not temporary intoxication
- •This represents permanent neurological damage from chronic inhalant exposure
Clinical Significance
This code identifies persisting dementia caused by inhalant exposure, representing irreversible neurotoxic brain damage. Substance-induced persisting dementia indicates permanent cognitive decline requiring long-term supportive care, cognitive rehabilitation, and ongoing supervision. Accurate documentation is essential for risk adjustment as these patients have substantially elevated care needs comparable to other dementia etiologies.
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
- ✓Cognitive assessment documenting persistent deficits in memory, executive function, or other cognitive domains
- ✓Provider documentation that the dementia is caused by substance use and persists beyond the period of acute intoxication or withdrawal
- ✓Assessment and plan addressing the substance use disorder with treatment approach documented