2027 ICD-10-CM Diagnosis Code F28Other psychotic disorder not due to a substance or known physiological condition

ICD-10-CM Codes›F01–F99›F20-F29›F28

ICD-10-CM F28
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

F28 is a billable ICD-10-CM diagnosis code for other psychotic disorder not due to a substance or known physiological condition. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 885, 974 through 976. Coders also document this condition as hallucinosis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Schizophrenia spectrum and other psychotic disorders.

For Medicare Advantage risk adjustment, F28 maps to CMS-HCC Category 152 (Psychosis, Except Schizophrenia) under the V28 model, adding a risk factor of about 0.484 for a community, non-dual, aged beneficiary in payment year 2027.

Code Identity

ICD-10-CM Code
F28
Billable Status
Yes — Valid for Submission
Code Describes
Other psychotic disorder not due to a substance or known physiological condition
Short Description
Oth psych disorder not due to a sub or known physiol cond
Chapter
F20-F29
Schizophrenia, schizotypal, delusional, and other non-mood psychotic disorders

Code Classification

ChapterF01–F99Mental and behavioural disorders
SectionF20-F29Schizophrenia, schizotypal, delusional, and other non-mood psychotic disorders
CategoryF28Other psychotic disorder not due to a substance or known physiological condition
This CodeF28Other psychotic disorder not due to a substance or known physiological condition

Medicare Risk Adjustment (HCC)Billing

F28 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 152— Psychosis, Except Schizophrenia
Payment HCC · PY 2027 one of 12 ICD-10-CM codes in this category
Risk Adjustment Factor (RAF) Weight
+0.484
community, non-dual, aged · ranges 0.208–0.579 across segments
Hierarchy
Superseded by HCC 151
a more severe related category takes the payment when both are reported
Prior Model (CMS-HCC V24)
HCC 58
V24 retired V28 pays 100% of MA risk scores since PY 2026
Other CMS Models
ESRD (V24): HCC 58
ESRD V24 weights: 0.111 dialysis, 0.145–0.572 functioning graft
Part D (RxHCC)
RxHCC 130 — Schizophrenia and Other Psychosis
also risk-adjusts in the Part D prescription drug model (V08)

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.

  • Hallucinosis

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to F28: its own notes plus those printed at 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 Chapter 5 (F01-F99) Mental and behavioural disorders applies to 872 codes
  • disorders of psychological development

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • Chronic hallucinatory psychosis
  • Other specified schizophrenia spectrum and other psychotic disorder

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 F28, its category, or a range that includes it.

Excludes1 3

These codes carry an Excludes1 note naming F28: they are not reported together with it, unless the two conditions are unrelated.

  • F53 Mental and behavioral disorders associated with the puerperium, not elsewhere classified
    psychosis in schizophrenia, schizotypal, delusional, and other psychotic disorders (F20-F29) names F20-F29, which includes this code
  • R44 Other symptoms and signs involving general sensations and perceptions
    hallucinations in schizophrenia, schizotypal and delusional disorders (F20-F29) names F20-F29, which includes this code
  • R46 Symptoms and signs involving appearance and behavior
    appearance and behavior in schizophrenia, schizotypal and delusional disorders (F20-F29) names F20-F29, which includes this code

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

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

CCSR MBD001
Schizophrenia spectrum and other psychotic disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Psychotic Disorders

Psychotic disorders are severe mental disorders that cause abnormal thinking and perceptions. People with psychoses lose touch with reality. Two of the main symptoms are delusions and hallucinations. Delusions are false beliefs, such as thinking that someone is plotting against you or that the TV is sending you secret messages.

Read the full article at MedlinePlus

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

Convert F28 to ICD-9-CMHistory

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

ICD-9-CM
298.9 Psychosis 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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About F28Overview

Is F28 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other psychotic disorder not due to a substance or known physiological condition on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does F28 group to?

When other psychotic disorder not due to a substance or known physiological condition is the principal diagnosis on an inpatient stay, it groups to MS-DRG 974, 976, 975, 885, with relative weights from 0.7879 to 3.0488 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of F28?

Under the General Equivalence Mappings, other psychotic disorder not due to a substance or known physiological condition converts to ICD-9-CM 298.9 (psychosis NOS). The mapping is approximate, so confirm the match fits the documentation.

What HCC is F28?

F28 (other psychotic disorder not due to a substance or known physiological condition) maps to CMS-HCC Category 152 (Psychosis, Except Schizophrenia), commonly written as HCC 152, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 58 under the retired V24 model. It also maps in the ESRD (V24) model. In the Part D prescription drug model it maps to RxHCC 130.

Does F28 risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, F28 adds a risk adjustment factor of about 0.484 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.208 to 0.579 depending on the payment segment). A more severe related category (HCC 151) supersedes it when both are reported. See the full factor table on the HCC 152 category page.