Excludes1 pair

P90 vs R56-

P90 and R56 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 R56
newborn convulsions and seizures (P90)
P90

Convulsions of newborn

Billable
Chapter 16
Certain conditions originating in the perinatal period
Section
P90-P96
Indexed under
  • Convulsions › infantile
  • Convulsions › newborn
  • Fit › newborn
  • Newborn › convulsion
  • Newborn › seizure
R56

Convulsions, not elsewhere classified

Not billable
Chapter 18
Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
Section
R50-R69

These two codes sit in different chapters of the Tabular List, which is usually the clearest signal that they describe different underlying processes rather than different degrees of the same one.

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