G21 vs G90.3
G21 and G90.3 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 G21
Shy-Drager syndrome (G90.3)
G90.3
Multi-system degeneration of the autonomic nervous system
Billable
- Chapter 6
- Diseases of the nervous system
- Section
- G89-G99
Use when the record says
- Neurogenic orthostatic hypotension [Shy-Drager]
Indexed under
- Shy-Drager syndrome
- Degeneration, degenerative › multi-system
- Hypotension › neurogenic, orthostatic (arterial) (constitutional)
- Parkinsonism › with neurogenic orthostatic hypotension (idiopathic) (primary)
- Hypotension › orthostatic › neurogenic (arterial) (constitutional)
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