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ICD-10-CM 2027 diagnosis code

F29Unspecified psychosis not due to a substance or known physiological condition

✓ Billable / specific

F29 is a valid, billable ICD-10-CM code for unspecified psychosis not due to a substance or known physiological condition. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.Short description: Unsp psychosis not due to a substance or known physiol cond

Looking up by condition? See ICD-10 code for Psychosis, ICD-10 code for Confusional psychosis.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About F29

F29 is the ICD-10-CM diagnosis code for unspecified psychosis not due to a substance or known physiological condition. It belongs to block F20-F29 (schizophrenia, schizotypal, delusional, and other non-mood psychotic disorders) and chapter 5 (mental, Behavioral and Neurodevelopmental disorders). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Don't report F29 together with the conditions in its Excludes1 note: mental disorder NOS (F99) and unspecified mental disorder due to known physiological condition (F09).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 885 (Psychoses, relative weight 1.3901), DRG 974 (HIV with Major Related Condition with MCC, relative weight 3.0506), DRG 975 (HIV with Major Related Condition with CC, relative weight 1.3252) and DRG 976 (HIV with Major Related Condition without CC/MCC, relative weight 0.8124), in MDC 19 (Mental Diseases and Disorders) and MDC 25 (Human Immunodeficiency Virus Infections), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 298.9 (unspecified psychosis).

Coding notes

Applicable toConditions and synonyms classified to this code
  • Psychosis NOS
  • Unspecified schizophrenia spectrum and other psychotic disorder
Excludes1Not coded here — never report together with this code
  • mental disorder NOS (F99)
  • unspecified mental disorder due to known physiological condition (F09)

Notes that apply from higher levels

Instructions written at a parent level also apply to F29.

Alphabetic index entries

5 entries

Terms in the official ICD-10-CM index that lead to F29.

Codes whose notes reference F29

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

ICD-9-CM equivalent

Converter →
  • 298.9Unspecified psychosisapproximate

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about F29

Is F29 billable?

Yes. F29 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can F29 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict F29 as a principal diagnosis.

Is F29 a CC or MCC?

No. F29 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does F29 group to?

F29 is used in the MS-DRG v44.0 logic for MS-DRG 885 (Psychoses), MS-DRG 974 (HIV with Major Related Condition with MCC), MS-DRG 975 (HIV with Major Related Condition with CC) and MS-DRG 976 (HIV with Major Related Condition without CC/MCC). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.

What is the ICD-9 code for F29?

The CMS General Equivalence Mappings map F29 to ICD-9-CM 298.9.