F20.3 vs F23
F20.3 and F23 can never be reported together. ICD-10-CM declares them mutually exclusive with an Excludes1 note, meaning the two conditions cannot occur in the same patient — so exactly one of them is correct for any given encounter.
The official note, declared on F20.3
acute schizophrenia-like psychotic disorder (F23)
F20.3
Undifferentiated schizophrenia
Billable
- Chapter 5
- Mental, Behavioral and Neurodevelopmental disorders
- Section
- F20-F29
Use when the record says
- Atypical schizophrenia
Indexed under
- Schizophrenia, schizophrenic › atypical
- Schizophrenia, schizophrenic › undifferentiated
F23
Brief psychotic disorder
Billable
- Chapter 5
- Mental, Behavioral and Neurodevelopmental disorders
- Section
- F20-F29
Use when the record says
- Paranoid reaction
- Psychogenic paranoid psychosis
Indexed under
- Bouffée délirante
- Oneirophrenia
- Attack, attacks › schizophreniform, brief
- Episode › psychotic
- Episode › schizophrenicNEC, brief
Excludes1 is not always absolute: where two conditions covered by the note are genuinely unrelated, CMS guidance permits reporting both. Document the reasoning rather than assuming it. More on Excludes1 vs Excludes2 · FY2027