2026 ICD-10-CM Diagnosis Code F18.99Inhalant use, unspecified with unspecified inhalant-induced disorder

ICD-10-CM Codes›F01–F99›F10-F19›F18

ICD-10-CM F18.99
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

F18.99 is a billable ICD-10-CM diagnosis code for inhalant use, unspecified with unspecified inhalant-induced disorder. 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
F18.99
Billable Status
Yes — Valid for Submission
Code Describes
Inhalant use, unspecified with unspecified inhalant-induced disorder
Short Description
Inhalant use, unsp with unsp inhalant-induced disorder
Parent Code
F18.9
Inhalant use, unspecified

Code Classification

ChapterF01–F99Mental and behavioural disorders
SectionF10-F19Mental and behavioral disorders due to psychoactive substance use
CategoryF18Inhalant related disorders
This CodeF18.99Inhalant use, unspecified with unspecified inhalant-induced disorder

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.

    • Use(of)
      • inhalants
        • with
          • unspecified disorder

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

Inhalants

Inhalants are substances that people inhale (breathe in) to get high. There are other substances that people might inhale, such as alcohol. But those are not called inhalants, because they can also be used another way. Inhalants are the substances that you can misuse only by inhaling them.

The full article covers:

  • What are inhalants?
  • What are the types of inhalants?
  • How do people use inhalants?
  • Who uses inhalants?
  • What are the signs that someone is using inhalants?
  • What are the health effects of using inhalants?
  • Are inhalants addictive?
  • Can inhalant misuse be prevented?

Read the full article at MedlinePlus

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

Convert F18.99 to ICD-9-CMHistory

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

ICD-9-CM
292.9 Drug mental disorder NOS
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 F18.99Overview

Is F18.99 (Inhalant use, unspecified) a billable code?

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

What MS-DRG does F18.99 group to?

When inhalant use, unspecified with unspecified inhalant-induced disorder 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 F18.99?

Under the General Equivalence Mappings, inhalant use, unspecified with unspecified inhalant-induced disorder converts to ICD-9-CM 292.9 (drug mental disorder NOS). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.