E72.2 vs E72.4
E72.2 and E72.4 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 E72.2
disorders of ornithine metabolism (E72.4)
E72.2
Disorders of urea cycle metabolism
Not billable
- Chapter 4
- Endocrine, nutritional and metabolic diseases
- Section
- E70-E88
E72.4
Disorders of ornithine metabolism
Billable
- Chapter 4
- Endocrine, nutritional and metabolic diseases
- Section
- E70-E88
Use when the record says
- Hyperammonemia-Hyperornithinemia-Homocitrullinemia syndrome
- Ornithinemia (types I, II)
- Ornithine transcarbamylase deficiency
Indexed under
- Hyperornithinemia
- Ornithine metabolism disorder
- Ornithinemia (Type I) (Type II)
- Deficiency, deficient › ornithine transcarbamylase
- Disorder › ornithine metabolism (of)
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