ICD-10 Code F20.3 – Undifferentiated Schizophrenia (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code F20.3 – Undifferentiated schizophrenia
What it is
F20.3 identifies schizophrenia when the presentation meets criteria for schizophrenia but does not fit paranoid, disorganized, or catatonic types. Use it when documentation states undifferentiated schizophrenia.
Clinical signs
Clinical features vary; refer to documentation. Commonly, patients may have delusions, hallucinations, disorganized thinking, or negative symptoms, without a single dominant subtype pattern.
When to use this code
Use F20.3 when the clinician diagnoses undifferentiated schizophrenia explicitly. It is appropriate when schizophrenia is confirmed and the record shows mixed features that do not clearly classify as another subtype. Check documentation if the subtype is unclear.
Do not use for
Do not use this code for schizoaffective disorder, brief psychotic disorder, or schizophrenia subtype documentation that is clearly paranoid, disorganized, or catatonic. Do not guess the diagnosis; check documentation.
Coding tip
Code F20.3 only when the provider documents undifferentiated schizophrenia or equivalent language.