Excludes1 pair

R26.0 vs R27-

R26.0 and R27 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 R27
ataxic gait (R26.0)
R26.0

Ataxic gait

Billable
Chapter 18
Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
Section
R25-R29
Use when the record says
  • Staggering gait
Indexed under
  • Staggering gait
  • Ataxia, ataxy, ataxic › gait
  • Gait abnormality › ataxic
  • Gait abnormality › staggering
R27

Other lack of coordination

Not billable
Chapter 18
Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
Section
R25-R29

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