E23.2 vs N25.1
E23.2 and N25.1 can never be reported together. ICD-10-CM declares them mutually exclusive with an Excludes1 note, meaning the two conditions cannot occur in the same patient — so exactly one of them is correct for any given encounter.
The official note, declared on E23.2
nephrogenic diabetes insipidus (N25.1)
E23.2
Diabetes insipidus
Billable
- Chapter 4
- Endocrine, nutritional and metabolic diseases
- Section
- E20-E35
Indexed under
- Deficiency, deficient › antidiuretic hormone
- Deficiency, deficient › vasopressin
- Diabetes, diabetic › insipidus (mellitus) (sugar)
- Hyposecretion › antidiuretic hormone
- Hyposecretion › vasopressin
N25.1
Nephrogenic diabetes insipidus
Billable
- Chapter 14
- Diseases of the genitourinary system
- Section
- N25-N29
Indexed under
- Diabetes, diabetic › insipidus › nephrogenic (mellitus) (sugar)
- Diabetes, diabetic › insipidus › vasopressin resistant (mellitus) (sugar)
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