Excludes1 pair

E22.2 vs E87.1

E22.2 and E87.1 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.

The official note, declared on E87.1
syndrome of inappropriate secretion of antidiuretic hormone (E22.2)
E22.2

Syndrome of inappropriate secretion of antidiuretic hormone

Billable
Chapter 4
Endocrine, nutritional and metabolic diseases
Section
E20-E35
Indexed under
  • Antidiuretic hormone syndrome
  • Schwartz-Bartter syndrome
  • Secretion › antidiuretic hormone, inappropriate
  • Syndrome › inappropriate secretion of antidiuretic hormone
  • Syndrome › Schwartz-Bartter
E87.1

Hypo-osmolality and hyponatremia

Billable
Chapter 4
Endocrine, nutritional and metabolic diseases
Section
E70-E88
Use when the record says
  • Sodium [Na] deficiency
Indexed under
  • Hyponatremia
  • Hypo-osmolality
  • Cramp › salt-depletion
  • Deficiency, deficient › natrium
  • Deficiency, deficient › salt

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