ICD-10 Code E70.8 – Other disorders of aromatic amino-acid metabolism (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code E70.8 – Other disorders of aromatic amino-acid metabolism
What it is
E70.8 identifies inherited or acquired disorders affecting the metabolism of aromatic amino acids such as phenylalanine, tyrosine, and tryptophan. Use it when documentation specifies another aromatic amino-acid metabolic disorder not named elsewhere.
Clinical signs
Clinical features vary; refer to documentation. Depending on the specific disorder, you may see developmental delay, neurologic symptoms, feeding problems, skin changes, or abnormal metabolic screening results.
When to use this code
Use E70.8 when the provider documents a disorder of aromatic amino-acid metabolism and no more specific ICD-10-CM code applies. It is appropriate for confirmed diagnoses, not for screening or a family history alone. Check the chart for the exact metabolic condition named.
Do not use for
Do not use this code for phenylketonuria, tyrosinemia, or other specific coded amino-acid disorders when a more precise code is documented. Do not use it for abnormal lab findings without a diagnosis.
Coding tip
Code the most specific metabolic disorder documented; if the note is vague, query for clarification before assigning E70.8.