ICD-10 Code E70.81 – Aromatic L-amino acid decarboxylase deficiency (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code E70.81 – Aromatic L-amino acid decarboxylase deficiency
What it is
E70.81 identifies aromatic L-amino acid decarboxylase deficiency, a rare inherited disorder that affects neurotransmitter production. Use it when the record documents this specific enzyme deficiency or a confirmed diagnosis.
Clinical signs
Clinical features vary; refer to documentation. Typical findings may include developmental delay, hypotonia, movement disorders, and episodes of oculogyric crisis or autonomic instability in standard references.
When to use this code
Use this code when the clinician documents aromatic L-amino acid decarboxylase deficiency, AADC deficiency, or a confirmed related genetic diagnosis. It also fits encounters for evaluation or follow-up of the known disorder. If the chart only says “neurotransmitter disorder,” check documentation before assigning E70.81.
Do not use for
Do not use E70.81 for nonspecific developmental delay, seizures, or movement symptoms without documented AADC deficiency. Do not code it when the condition is only suspected or under workup.
Coding tip
Confirm the exact diagnosis wording in the assessment, because this code is for the specific inherited deficiency, not a general neurologic symptom.