ICD-10 Code E70.41 – Histidinemia (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code E70.41 – Histidinemia
What it is
Histidinemia is an inherited disorder of histidine metabolism. Use this code when documentation identifies the condition specifically, not just an abnormal newborn screen.
Clinical signs
Clinical features vary; refer to documentation. It may be found through newborn screening or metabolic testing, and some patients are asymptomatic while others have developmental or speech concerns.
When to use this code
Use E70.41 when the provider documents histidinemia as an active diagnosis or confirmed metabolic disorder. It is also appropriate when the record clearly states the condition is being evaluated or followed. Do not code from a screening result alone without confirmation.
Do not use for
Do not use this code for nonspecific amino acid abnormalities, suspected metabolic disease, or a positive screen without a documented diagnosis. Check documentation if the chart only mentions elevated histidine.
Coding tip
Confirm that histidinemia is explicitly named in the assessment, problem list, or discharge diagnosis before assigning E70.41.