F18.988
BillableInhalant use, unspecified with other inhalant-induced disorder
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is F18.988 an HCC code?
Yes. F18.988 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 F18.988
For F18.988 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 F18.988 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
F18.988 is the ICD-10-CM diagnosis code for inhalant use, unspecified with other inhalant-induced disorder. A person with unspecified inhalant use who has developed other mental or physical health problems caused by the inhalant exposure. F18.988 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, F18.988 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, F18.988 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.
Use this code when inhalant-induced disorders other than anxiety, psychosis, or dementia are present. Because F18.988 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 F18.988 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use this code when inhalant-induced disorders other than anxiety, psychosis, or dementia are present
- •Document the specific inhalant-induced disorder in the medical record for clarity
Clinical Significance
This code captures other specified substance-induced disorders from inhalant use that do not fit into the standard categories of psychosis, mood, anxiety, or sleep disorders. These may include movement disorders, neurocognitive changes, or other organ-specific complications. Accurate coding of these additional complications reflects the true clinical burden and supports appropriate risk adjustment.
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
- ✓Description of the specific substance-induced disorder that does not fit standard categories (e.g., movement disorder, olfactory disorder, obsessive-compulsive features)
- ✓Assessment and plan addressing the substance use disorder with treatment approach documented