E87- vs O21.1
E87 and O21.1 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.
Other disorders of fluid, electrolyte and acid-base balance
- Chapter 4
- Endocrine, nutritional and metabolic diseases
- Section
- E70-E88
Hyperemesis gravidarum with metabolic disturbance
- Chapter 15
- Pregnancy, childbirth and the puerperium
- Section
- O20-O29
- Hyperemesis gravidarum, starting before the end of the 20th week of gestation, with metabolic disturbance such as carbohydrate depletion
- Hyperemesis gravidarum, starting before the end of the 20th week of gestation, with metabolic disturbance such as dehydration
- Hyperemesis gravidarum, starting before the end of the 20th week of gestation, with metabolic disturbance such as electrolyte imbalance
- Hyperemesis › gravidarum › severe (with metabolic disturbance)
- Imbalance › electrolyte › due to hyperemesis gravidarum
- Hyperemesis › gravidarum › with › carbohydrate depletion
- Hyperemesis › gravidarum › with › dehydration
- Hyperemesis › gravidarum › with › electrolyte imbalance
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