2027 ICD-10-CM Diagnosis Code F18.259Inhalant dependence with inhalant-induced psychotic disorder, unspecified

ICD-10-CM Codes›F01–F99›F10-F19›F18

ICD-10-CM F18.259
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

F18.259 is a billable ICD-10-CM diagnosis code for inhalant dependence with inhalant-induced psychotic disorder, unspecified. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 894 through 897. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 11 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Inhalant-related disorders and Schizophrenia spectrum and other psychotic disorders.

For Medicare Advantage risk adjustment, F18.259 maps to CMS-HCC Category 135 (Drug Use with Psychotic Complications) under the V28 model, adding a risk factor of about 0.424 for a community, non-dual, aged beneficiary in payment year 2027.

Code Identity

ICD-10-CM Code
F18.259
Billable Status
Yes — Valid for Submission
Code Describes
Inhalant dependence with inhalant-induced psychotic disorder, unspecified
Short Description
Inhalant depend w inhalnt-induce psychotic disorder, unsp
Parent Code
Inhalant dependence with inhalant-induced psychotic disorder

Code Classification

ChapterF01–F99Mental and behavioural disorders
SectionF10-F19Mental and behavioral disorders due to psychoactive substance use
CategoryF18Inhalant related disorders
This CodeF18.259Inhalant dependence with inhalant-induced psychotic disorder, unspecified

Medicare Risk Adjustment (HCC)Billing

F18.259 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2027.

CMS-HCC V28 Category (Payment Model)
HCC 135— Drug Use with Psychotic Complications
Payment HCC · PY 2027 one of 97 ICD-10-CM codes in this category
Risk Adjustment Factor (RAF) Weight
+0.424
community, non-dual, aged · ranges 0.297–1.181 across segments
Hierarchy
Supersedes HCC 136, HCC 137, HCC 138, and HCC 139
less severe related categories are not paid alongside HCC 135
Prior Model (CMS-HCC V24)
HCC 54
V24 retired V28 pays 100% of MA risk scores since PY 2026
Other CMS Models
PACE (CMS-HCC V22): HCC 54 · ESRD (V21): HCC 54 · ESRD (V24): HCC 54
ESRD V21 weights: 0.048 dialysis, 0.112–0.352 functioning graft · ESRD V24 weights: 0.111 dialysis, 0.172–1.071 functioning graft
Part D (RxHCC)
Not mapped
F18.259 does not risk-adjust in the RxHCC prescription drug model

Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to F18.259: its own notes plus those printed at F18.2, F18, and Chapter 5. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From F18 Inhalant related disorders applies to 39 codes
  • volatile solvents
From Chapter 5 (F01-F99) Mental and behavioural disorders applies to 872 codes
  • disorders of psychological development

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From F18.2 Inhalant dependence applies to 13 codes

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 5 (F01-F99) Mental and behavioural disorders applies to 872 codes
  • symptoms, signs and abnormal clinical laboratory findings, not elsewhere classified (R00-R99)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name F18.259, its category, or a range that includes it.

Excludes1 2

These codes carry an Excludes1 note naming F18.259: they are not reported together with it, unless the two conditions are unrelated.

  • F18.1 Inhalant abuse
    inhalant dependence (F18.2-) names F18.2-, which includes this code
  • F18.9 Inhalant use, unspecified
    inhalant dependence (F18.2-) names F18.2-, which includes this code

Index to Diseases and InjuriesGuidance

Clinical ClassificationClinical

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

CCSR MBD023
Inhalant-related disorders
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR MBD001
Schizophrenia spectrum and other psychotic disorders
Default principal diagnosis: inpatient No · outpatient No

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 F18.259 to ICD-9-CMHistory

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

ICD-9-CM
292.89 Drug mental disorder NEC
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.
ICD-9-CM
304.60 Drug depend NEC-unspec
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About F18.259Overview

Is F18.259 (Inhalant dependence with inhalant-induced psychotic disorder) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report inhalant dependence with inhalant-induced psychotic disorder, unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does F18.259 group to?

When inhalant dependence with inhalant-induced psychotic disorder, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 894, 897, 895, 896, with relative weights from 0.6272 to 1.6610 depending on complications. Higher weights mean higher Medicare reimbursement.

Is F18.259 a CC or MCC?

CMS lists F18.259 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 11 closely related codes in its exclusion list.

Can F18.259 be reported with a code from F18.1?

Not as a rule. The Excludes1 note at F18.2, which applies to F18.259, lists "inhalant abuse (F18.1-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

What is the ICD-9 equivalent of F18.259?

Under the General Equivalence Mappings, inhalant dependence with inhalant-induced psychotic disorder, unspecified converts to ICD-9-CM 292.89 (drug mental disorder NEC) and 304.60 (drug depend NEC-unspec). The mapping is approximate, so confirm the match fits the documentation.

What HCC is F18.259?

F18.259 (inhalant dependence with inhalant-induced psychotic disorder, unspecified) maps to CMS-HCC Category 135 (Drug Use with Psychotic Complications), commonly written as HCC 135, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 54 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. It does not map to any RxHCC in the Part D prescription drug model.

Does F18.259 risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, F18.259 adds a risk adjustment factor of about 0.424 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.297 to 1.181 depending on the payment segment). HCC 135 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 135 category page.