E88.42 MERRF syndrome

The ICD-10-CM code for MERRF syndrome is E88.42 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

4: Endocrine, nutritional and metabolic diseases (E00-E89)

Section

E70-E88: Metabolic disorders (E70-E88)

Category E88

30 codes (24 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to E88.42:

• MERRF syndrome (myoclonic epilepsy associated with ragged-red fiber)
• Syndrome › MERRF (myoclonic epilepsy associated with ragged-red fibers)
• Disorder (of) › metabolism NOS › mitochondrial › MERRF syndrome (myoclonic epilepsy associated with ragged-red fibers)

Inclusion Terms

• Myoclonic epilepsy associated with ragged-red fibers

U.S. Hospital Utilization

• An estimated 90 U.S. inpatient stays in 2023 included E88.42 among the documented diagnoses.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

Official Coding Guidelines

Diabetes mellitus (TOC entry)

a. Diabetes mellitus ................................................................................................................... 39

Obesity (TOC entry)

b. Obesity .................................................................................................................................. 42

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool
• AHRQ — HCUP National Inpatient Sample, Frequencies by Diagnosis Code (2016–2023)