Excludes1 pair
F20.3 vs F23
F20.3 and F23 are not coded together. ICD-10-CM declares them mutually exclusive with an Excludes1 note — the two conditions are not expected to occur together, so exactly one of them is normally correct for a given encounter. The Official Guidelines carve out one exception: if the two conditions are clearly unrelated to each other, both may be reported.
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 (form)
- Schizophrenia, schizophrenic › undifferentiated (type)
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 › schizophrenic NEC, brief (acute)
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