ICD10BillableValid for clinical use

ICD-10 Code F20.3: Undifferentiated schizophrenia

F20.3 is a billable ICD-10 diagnosis code used to classify Undifferentiated schizophrenia in medical records and claims. You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records. ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Mental, Behavioral and Neurodevelopmental disorders (F01-F99).

Reviewed by HealthAssure Clinical TeamUpdated 26 May 2026

What is this code?

ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Mental, Behavioral and Neurodevelopmental disorders (F01-F99).

When is it used?

  • May be used when a clinician documents undifferentiated schizophrenia in a patient's medical record.
  • May appear in hospital records, claims, referrals, and clinical documentation.
  • This code can be used as a clinically usable diagnosis entry in standardized coding workflows.

What it does not mean

  • A code alone does not explain severity, treatment plan, or outcome.
  • A medical code should not be treated as a substitute for a doctor's diagnosis or advice.

Code hierarchy

chapter
5Mental, Behavioral and Neurodevelopmental disorders (F01-F99)
block
F20-F29Schizophrenia, schizotypal, delusional, and other non-mood psychotic disorders
category
F20Schizophrenia
currentF20

Official coding notes

Inclusion terms
  • Atypical schizophrenia
Excludes1 (do not code together)
  • acute schizophrenia-like psychotic disorder (F23)
Excludes2 (may code together if documented)
  • post-schizophrenic depression (F32.89)

Where you may see this code

You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.

Coding guidelines

Compatibility

Legacy and official ICD code match exactly.
Legacy codes
F20.3

Common synonyms

Undifferentiated schizophrenia

Frequently asked questions

Code details

CodeF20.3
SystemICD10
Display nameUndifferentiated schizophrenia
ChapterMental, Behavioral and Neurodevelopmental disorders (F01-F99)
BlockSchizophrenia, schizotypal, delusional, and other non-mood psychotic disorders

Flags

BillableYes
Valid clinical useYes

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

Index terms

Matched terms
Schizophrenia, schizophrenicSchizophrenia, schizophrenic

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.

ICD-10 Code F20.3 for Undifferentiated schizophrenia | HealthAssure