2027 ICD-10-CM Diagnosis Code F18.959Inhalant use, unspecified with inhalant-induced psychotic disorder, unspecified
F18.959 is a billable ICD-10-CM diagnosis code for inhalant use, unspecified 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. Coders also document this condition as psychosis caused by inhalant. 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, F18.959 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
Code Classification
Medicare Risk Adjustment (HCC)Billing
F18.959 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.
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.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Psychosis caused by inhalant
- Psychotic disorder caused by volatile inhalant
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to F18.959: its own notes plus those printed at F18.9, 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.
- volatile solvents
- disorders of psychological development
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
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.
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name F18.959, its category, or a range that includes it.
Excludes1 2
These codes carry an Excludes1 note naming F18.959: they are not reported together with it, unless the two conditions are unrelated.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
psychotic disorder F18.959
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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 F18.959 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About F18.959Overview
Is F18.959 a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report inhalant use, unspecified with inhalant-induced psychotic disorder, unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does F18.959 group to?
When inhalant use, unspecified 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.
Can F18.959 be reported with a code from F18.1?
Not as a rule. The Excludes1 note at F18.9, which applies to F18.959, 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 F18.959?
Under the General Equivalence Mappings, inhalant use, unspecified with inhalant-induced psychotic disorder, unspecified converts to ICD-9-CM 292.89 (drug mental disorder NEC). The mapping is approximate, so confirm the match fits the documentation.
What HCC is F18.959?
F18.959 (inhalant use, unspecified 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 F18.959 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, F18.959 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.
