ICD-10 Code E72.21 – Argininemia (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code E72.21 – Argininemia
What it is
Argininemia is a rare inherited disorder of the urea cycle that causes arginine to build up in the blood. Use this code when the diagnosis is documented as argininemia.
Clinical signs
Clinical features vary; refer to documentation. Commonly reported findings include developmental delay, spasticity, and episodes related to hyperammonemia in affected patients.
When to use this code
Use E72.21 when the provider documents argininemia, including confirmed hereditary arginase deficiency. It may also apply when the record clearly identifies the disorder during metabolic or genetic evaluation. If the note only says “urea cycle disorder,” check documentation for the specific type.
Do not use for
Do not use this code for nonspecific hyperammonemia or other urea cycle disorders without documentation of argininemia. Check documentation if the diagnosis is uncertain or listed only as a rule-out.
Coding tip
Code the documented metabolic diagnosis, not just the presenting encephalopathy or ammonia abnormality.