ICD-10 Code F18.9 – Inhalant use, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code F18.9 – Inhalant use, unspecified
What it is
F18.9 identifies inhalant use when the specific substance is not documented. Use it for nondependent inhalant use involving fumes, vapors, or gases, but only when the record does not support a more specific code.
Clinical signs
Clinical features vary; refer to documentation. Commonly noted findings may include intoxication, dizziness, euphoria, slurred speech, poor coordination, or altered behavior after inhalant exposure.
When to use this code
Use F18.9 when the provider documents inhalant use without naming the agent or specifying dependence, abuse, or other associated disorder. It may also fit brief chart entries such as “inhalant use” or “huffing,” when details are limited.
If the substance is identified, code the more specific inhalant-related diagnosis instead. Check documentation for coexisting intoxication, withdrawal, or toxic effects, because those may require additional coding.
Do not use for
Do not use this code for dependence, abuse, or intoxication when those conditions are documented. Also avoid it when a specific inhalant or toxic exposure is identified and a more precise code is available.
Coding tip
Query the provider when “inhalant use” is vague, so you can confirm the substance and whether the diagnosis is use, abuse, dependence, or intoxication.