2026 ICD-10-CM Diagnosis Code F18.121Inhalant abuse with intoxication delirium

ICD-10-CM Codes›F01–F99›F10-F19›F18

ICD-10-CM F18.121
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

F18.121 is a billable ICD-10-CM diagnosis code for inhalant abuse with intoxication delirium. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 894 through 897. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Inhalant-related disorders.

Code Identity

ICD-10-CM Code
F18.121
Billable Status
Yes — Valid for Submission
Code Describes
Inhalant abuse with intoxication delirium
Short Description
Inhalant abuse with intoxication delirium
Same as the full description in the CMS dataset.
Parent Code
F18.12
Inhalant abuse with intoxication

Code Classification

ChapterF01–F99Mental and behavioural disorders
SectionF10-F19Mental and behavioral disorders due to psychoactive substance use
CategoryF18Inhalant related disorders
This CodeF18.121Inhalant abuse with intoxication delirium

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Abuse
      • drug NEC (non-dependent)
        • inhalant
          • with
            • intoxication
              • with delirium
    • Delirium, delirious(acute or subacute) (not alcohol- or drug-induced)
      • due to (secondary to)
        • inhalant intoxication (acute)
          • in
            • abuse
    • Disorder(of)
      • inhalant use
        • mild
          • with
            • inhalant intoxication delirium

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR MBD023
Inhalant-related disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Delirium

Delirium is a mental state in which you are confused, disoriented, and not able to think or remember clearly. It usually starts suddenly. It is often temporary and treatable.

The full article covers:

  • What is delirium?
  • What causes delirium?
  • Who is more likely to get delirium?
  • What are the symptoms of delirium?
  • How is delirium diagnosed?
  • What are the treatments for delirium?
  • Can delirium be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert F18.121 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
292.81 Drug-induced delirium
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About F18.121Overview

Is F18.121 (Inhalant abuse with intoxication) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report inhalant abuse with intoxication delirium on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does F18.121 group to?

When inhalant abuse with intoxication delirium is the principal diagnosis on an inpatient stay, it groups to MS-DRG 894, 895, 896, 897, with relative weights from 0.6169 to 1.7451 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of F18.121?

Under the General Equivalence Mappings, inhalant abuse with intoxication delirium converts to ICD-9-CM 292.81 (drug-induced delirium). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.