ICD-10 Code F16.221 – Hallucinogen dependence with intoxication with delirium (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code F16.221 – Hallucinogen dependence with intoxication with delirium
What it is
This code identifies hallucinogen dependence with current intoxication and delirium. It applies when a patient has a hallucinogen use disorder plus an acute delirious state caused by recent use.
Clinical signs
Typical findings include impaired attention, disorganized thinking, altered awareness, and confusion during intoxication. Clinical features vary; refer to documentation for the specific hallucinogen, severity, and whether delirium is explicitly diagnosed.
When to use this code
Use this code when the record documents both hallucinogen dependence and intoxication with delirium. You may see it in emergency, inpatient, or psychiatric notes describing acute mental status change after hallucinogen use.
Choose it only when delirium is linked to the intoxication episode, not merely intoxication alone. If dependence is not documented, or delirium is absent, check documentation before coding.
Do not use for
Do not use this code for hallucinogen use without dependence, or for intoxication without delirium. Do not assign it when delirium has another documented cause.
Coding tip
Verify that dependence and delirium are both stated in the record before assigning F16.221.