MCMCB Pro
E88.4

E88.4Mitochondrial metabolism disorders

Non-billable headerICD-10-CM

E88.4 is a non-billable header ICD-10-CM code for mitochondrial metabolism disorders. It cannot be billed on its own: choose one of the more specific child codes below.

Excludes1 — never code together

These conditions cannot occur together. Billing both on the same encounter is a denial.

  • disorders of pyruvate metabolism (E74.4)
  • Kearns-Sayre syndrome (H49.81)
  • Leber's disease (H47.22)
  • Leigh's encephalopathy (G31.82)
  • Mitochondrial myopathy, NEC (G71.3)
  • Reye's syndrome (G93.7)

Other codes that can never be billed with E88.4

These codes carry an Excludes1 note pointing at E88.4. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading E88.4 alone.

  • G71.3Mitochondrial myopathy, not elsewhere classified

Risk adjustment

E88.4 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.

Code to one of these instead E88.4

5 child codes. Green means billable.

Related codes at this level

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

Questions about E88.4

Is E88.4 a billable ICD-10-CM code?
No. E88.4 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does E88.4 sit in the tabular list?
Endocrine, nutritional and metabolic diseases (E00-E89), in the block Metabolic disorders (E70-E88).
What cannot be coded together with E88.4?
E88.4 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.
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.