ICD-10 Code E88.4 – Mitochondrial Metabolism Disorders (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code E88.4 – Mitochondrial metabolism disorders
What it is
E88.4 identifies inherited or acquired disorders that impair mitochondrial energy production and metabolism. You use it for conditions where the record documents a mitochondrial metabolic disorder, not a single organ complaint.
Clinical signs
Clinical features vary; refer to documentation. Commonly documented findings include exercise intolerance, muscle weakness, neurologic involvement, lactic acidosis, or multisystem disease affecting the brain, heart, or muscles.
When to use this code
Use this code when the provider clearly diagnoses a mitochondrial metabolism disorder or mitochondrial disease. It may also apply when the chart links symptoms to a confirmed mitochondrial disorder, even if the exact subtype is not named. Check documentation for the specific diagnosis and any associated manifestations.
Do not use for
Do not use E88.4 for nonspecific fatigue, isolated myopathy, or metabolic abnormalities without a documented mitochondrial disorder. If the note names a different inherited metabolic condition, code that diagnosis instead.
Coding tip
Code the confirmed mitochondrial disorder first, then add documented manifestations only when the record supports them.