F18.24
BillableInhalant dependence with inhalant-induced mood disorder
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is F18.24 an HCC code?
Yes. F18.24 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 F18.24
For F18.24 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 F18.24 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
F18.24 is the ICD-10-CM diagnosis code for inhalant dependence with inhalant-induced mood disorder. A person who is dependent on inhalants and has developed a mood disorder (such as depression or bipolar disorder) directly caused by the inhalant use. F18.24 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, F18.24 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, F18.24 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.
Ensure the mood disorder is documented as inhalant-induced rather than a primary psychiatric condition. Because F18.24 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 F18.24 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Ensure the mood disorder is documented as inhalant-induced rather than a primary psychiatric condition
- •Consider the temporal relationship between inhalant use and mood disorder onset
Clinical Significance
Inhalant dependence with induced mood disorder captures chronic inhalant users who have developed depression, mania, or emotional dysregulation directly caused by neurotoxic effects of inhalants. Toluene and other solvents damage frontal lobe white matter, producing mood disturbances that may persist even after cessation.
Documentation Requirements
- ✓Documentation of inhalant dependence
- ✓Specific mood symptoms (depressive, manic, irritable, mixed)
- ✓Provider statement linking mood disturbance to inhalant use
- ✓Neuropsychological assessment if available
- ✓Brain imaging findings when available (white matter changes)
- ✓Treatment plan addressing both dependence and mood disorder
Commonly Confused Codes
- •F18.14 — Inhalant abuse with induced mood disorder; use when abuse rather than dependence
- •F18.280 — Inhalant dependence with induced anxiety; anxiety and mood are different
- •F32.9 — Major depressive disorder, unspecified; use for primary depression
- •F18.20 — Inhalant dependence, uncomplicated; use when no induced disorder present