Excludes1 pair

R40- vs R55

R40 and R55 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 R55
unconsciousness NOS (R40.2-)
R40

Somnolence, stupor and coma

Not billable
Chapter 18
Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
Section
R40-R46
R55

Syncope and collapse

Billable
Chapter 18
Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
Section
R50-R69
Use when the record says
  • Blackout
  • Fainting
  • Vasovagal attack
Indexed under
  • Blackout
  • Collapse
  • Fainting (fit)
  • Near-syncope
  • Pre-syncope

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