ICD-10 Code E72.4 – Disorders of ornithine metabolism (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code E72.4 – Disorders of ornithine metabolism
What it is
E72.4 identifies inherited disorders that affect how the body processes ornithine, an amino acid involved in the urea cycle. Use it for documented ornithine metabolism abnormalities, including ornithine transcarbamylase-related conditions when specified as such.
Clinical signs
Clinical features vary; refer to documentation. Patients may present with signs of a urea cycle disorder, such as poor feeding, vomiting, lethargy, confusion, or recurrent hyperammonemia, but you should code only what is documented.
When to use this code
Use E72.4 when the provider documents a disorder of ornithine metabolism as the diagnosis or confirms an inherited ornithine-related metabolic defect. It is also appropriate when the record describes a specific ornithine pathway disorder without a more precise ICD-10-CM option. Check documentation if the note only mentions abnormal amino acid testing.
Do not use for
Do not use this code for nonspecific ammonia elevation without a diagnosed ornithine disorder. Do not assign it when the chart documents another metabolic condition or a different urea cycle defect more specifically.
Coding tip
Code the most specific documented metabolic diagnosis, and query the provider if the record only says “ornithine abnormality” or “possible urea cycle disorder.”