F18.229
BillableInhalant dependence with intoxication, unspecified
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is F18.229 an HCC code?
Yes. F18.229 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 F18.229
For F18.229 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 F18.229 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
F18.229 is the ICD-10-CM diagnosis code for inhalant dependence with intoxication, unspecified. A person who is dependent on inhalants and is currently intoxicated, but the severity or specific characteristics of the intoxication are not documented. F18.229 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, F18.229 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, F18.229 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.
This is a less specific code; attempt to determine if intoxication is uncomplicated or with delirium. Because F18.229 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 F18.229 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This is a less specific code; attempt to determine if intoxication is uncomplicated or with delirium
- •Use only when intoxication details cannot be determined from documentation
Clinical Significance
Inhalant dependence with unspecified intoxication indicates documentation does not clarify whether delirium is present during intoxication. Given the high mortality risk of inhalant intoxication, this code should prompt immediate provider queries to determine the clinical severity and guide appropriate treatment.
Documentation Requirements
- ✓Documentation of inhalant dependence with active intoxication
- ✓Provider query for delirium status
- ✓Available clinical observations during intoxication
- ✓Vital signs and monitoring data
- ✓Reason specificity cannot be achieved
Commonly Confused Codes
- •F18.220 — With uncomplicated intoxication; preferred when delirium is ruled out
- •F18.221 — With intoxication delirium; preferred when delirium is documented
- •F18.20 — Inhalant dependence, uncomplicated; use when no intoxication is occurring
- •F18.129 — Inhalant abuse with intoxication, unspecified; use for abuse