Excludes1 pair

E87- vs O08.5

E87 and O08.5 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 E87
electrolyte imbalance following ectopic or molar pregnancy (O08.5)
E87

Other disorders of fluid, electrolyte and acid-base balance

Not billable
Chapter 4
Endocrine, nutritional and metabolic diseases
Section
E70-E88
O08.5

Metabolic disorders following an ectopic and molar pregnancy

Billable
Chapter 15
Pregnancy, childbirth and the puerperium
Section
O00-O08
Indexed under
  • Complication › ectopic pregnancy › metabolic disorder
  • Complication › molar pregnancy NOS › metabolic disorder
  • Electrolyte imbalance › with › ectopic pregnancy
  • Electrolyte imbalance › with › molar pregnancy
  • Imbalance › electrolyte › following ectopic or molar pregnancy

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