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E88.42

E88.42MERRF syndrome

Billable / specific codeICD-10-CM

E88.42 is a billable, specific ICD-10-CM code for merrf syndrome. It is valid for submission on a claim.

Code also

Both codes may be needed to describe the encounter fully. Sequencing depends on the reason for the visit.

  • progressive myoclonic epilepsy (G40.3-)

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

  • Myoclonic epilepsy associated with ragged-red fibers

Risk adjustment

E88.42 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Medicare coverage

E88.42 is named in 1 Medicare coverage policy 1 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A57224Billing and Coding: Respiratory Care

How E88.42 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to E88.42.

  • MERRF syndrome(myoclonic epilepsy associated with ragged-red fiber)
  • SyndromeMERRF(myoclonic epilepsy associated with ragged-red fibers)
  • Disordermetabolism NOSmitochondrialMERRF syndrome(myoclonic epilepsy associated with ragged-red fibers)

Related codes at this level

Codes that share E88.4. If E88.42 is not quite right, the correct code is usually one of these.

Questions about E88.42

Is E88.42 a billable ICD-10-CM code?
Yes. E88.42 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does E88.42 sit in the tabular list?
Endocrine, nutritional and metabolic diseases (E00-E89), in the block Metabolic disorders (E70-E88).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.