2026 ICD-10-CM Diagnosis Code F28Other psychotic disorder not due to a substance or known physiological condition
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 2026 (October 1, 2025 through September 30, 2026) 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 2026.
Code Identity
Code Classification
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 2026.
Source: CMS Payment Year 2026 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
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Chronic hallucinatory psychosis
- Other specified schizophrenia spectrum and other psychotic disorder
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Disorder (of) See Also: Disease;
Insanity, insane See Also: Psychosis;
confusional F28
involutional F28
specified NEC F28
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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
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Convert F28 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
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, 2025 through September 30, 2026.
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 885, 974, 975, 976, with relative weights from 0.8945 to 2.8860 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 2026. 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.
