R27 vs R42
R27 and R42 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 R27
vertigo NOS (R42)
R27
Other lack of coordination
Not billable
- Chapter 18
- Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
- Section
- R25-R29
R42
Dizziness and giddiness
Billable
- Chapter 18
- Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
- Section
- R40-R46
Use when the record says
- Light-headedness
- Vertigo NOS
Indexed under
- Dizziness
- Dysequilibrium
- Giddiness
- Swimming in the head
- Vertigo
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