ICD-10 Code E88.40 – Mitochondrial metabolism disorder, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code E88.40 – Mitochondrial metabolism disorder, unspecified
What it is
This code identifies a mitochondrial metabolism disorder when the record does not specify the exact type. It signals a disorder of mitochondrial energy production, but the documentation is too vague for a more specific code.
Clinical signs
Clinical features vary; refer to documentation. Commonly reported findings may include muscle weakness, exercise intolerance, neurologic involvement, or multisystem disease, but you should code only what is documented.
When to use this code
Use E88.40 when the provider documents a mitochondrial metabolism disorder without naming a specific syndrome or genetic subtype. It is also appropriate when the note confirms a mitochondrial disorder but the details are insufficient for a more specific code. Check documentation if the chart suggests a known named condition.
Do not use for
Do not use this code for a documented, more specific mitochondrial disorder. Do not use it when the condition is not confirmed or when the record only mentions a suspected metabolic problem.
Coding tip
Code the most specific mitochondrial diagnosis available, and query for clarification if the provider’s documentation is nonspecific.