ICD-10 Code F18.99 – Inhalant use, unspecified with unspecified inhalant-induced disorder (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code F18.99 – Inhalant use, unspecified with unspecified inhalant-induced disorder
What it is
This code identifies inhalant use when the specific substance is not documented and the related inhalant-induced disorder is also not specified. Use it when the record confirms inhalant involvement but does not give a clearer diagnosis.
Clinical signs
Clinical features vary; refer to documentation. Records may mention intoxication, altered mental status, or other inhalant-related effects, but the exact disorder must remain unspecified for this code.
When to use this code
Use F18.99 when the provider documents inhalant use and an inhalant-induced condition, but does not name the substance or the exact disorder. It is appropriate for incomplete or nonspecific documentation that still supports an inhalant-related diagnosis. If the chart later identifies a more specific inhalant disorder, code that instead.
Do not use for
Do not use this code when the inhalant substance or the induced disorder is clearly documented and a more specific code is available. Check documentation if the record instead describes another substance use disorder.
Coding tip
Confirm both the inhalant use and the unspecified induced disorder are documented before assigning this code.