2026 ICD-10-CM Diagnosis Code E88.42MERRF syndrome
ICD-10-CM Codes›E00–E89›E70-E88›E88
- Billable — Valid for Submission
- Chronic Condition
E88.42 is a billable ICD-10-CM diagnosis code for MERRF syndrome. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). Coders also document this condition as myoclonic epilepsy with ragged red fibers. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified nutritional and metabolic disorders.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Myoclonic epilepsy with ragged red fibers
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Myoclonic epilepsy associated with ragged-red fibers
Code Also
- progressive myoclonic epilepsy G40.3
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
A "code also" note instructs that two codes may be required to fully describe a condition, but this note does not provide sequencing direction.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
- Disorder (of) - See Also: Disease;
- Syndrome - See Also: Disease;
External Cause of Injuries IndexGuidance
References for this code in the External Cause of Injuries Index.
- Disorder(of)
- metabolism NOS
- mitochondrial
- MERRF syndrome (myoclonic epilepsy associated with ragged-red fibers)
- MERRF syndrome(myoclonic epilepsy associated with ragged-red fiber)
- Syndrome
- MERRF (myoclonic epilepsy associated with ragged-red fibers)
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
MERRF Syndrome
a mitochondrial encephalomyopathy characterized clinically by a mixed seizure disorder, myoclonus, progressive ataxia, spasticity, and a mild myopathy. dysarthria, optic atrophy, growth retardation, deafness, and dementia may also occur. this condition tends to present in childhood and to be transmitted via maternal lineage. muscle biopsies reveal ragged-red fibers and respiratory chain enzymatic defects. (from adams et al., principles of neurology, 6th ed, p986)
Patient EducationClinical
Metabolic Disorders
Metabolism is the process your body uses to get or make energy from the food you eat. Food is made up of proteins, carbohydrates, and fats. Chemicals in your digestive system break the food parts down into sugars and acids, your body's fuel.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert E88.42 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About E88.42Overview
Is E88.42 (Mitochondrial metabolism disorders) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report MERRF syndrome on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What is the ICD-9 equivalent of E88.42?
Under the General Equivalence Mappings, MERRF syndrome converts to ICD-9-CM 277.87 (dis mitochondrial metab). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:
- The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
- The condition places limitations on self-care, independent living, and social interactions.
