Excludes1 pair

K65- vs O08.0

K65 and O08.0 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 K65
peritonitis with or following abortion or ectopic or molar pregnancy (O00-O07, O08.0)
K65

Peritonitis

Not billable
Chapter 11
Diseases of the digestive system
Section
K65-K6A
O08.0

Genital tract and pelvic infection following ectopic and molar pregnancy

Billable
Chapter 15
Pregnancy, childbirth and the puerperium
Section
O00-O08
Use when the record says
  • Endometritis following ectopic and molar pregnancy
  • Oophoritis following ectopic and molar pregnancy
  • Parametritis following ectopic and molar pregnancy
  • Pelvic peritonitis following ectopic and molar pregnancy
  • Salpingitis following ectopic and molar pregnancy
  • Salpingo-oophoritis following ectopic and molar pregnancy
Indexed under
  • Deciduitis › following ectopic or molar pregnancy
  • Endometritis › with ectopic pregnancy
  • Lymphadenitis › with ectopic or molar pregnancy
  • Lymphadenitis › following ectopic or molar pregnancy
  • Peritonitis › 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