E88.43
BillableDisorders of mitochondrial tRNA synthetases
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is E88.43 an HCC code?
Yes. E88.43 maps to Other Significant Endocrine and Metabolic Disorders under the V24 model but is not retained in V28.
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
MEAT Criteria for E88.43
For E88.43to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically — it has to be re-documented and supported each calendar year.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed E88.43 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
E88.43 is the ICD-10-CM diagnosis code for disorders of mitochondrial trna synthetases. A group of rare inherited disorders affecting the enzymes responsible for assembling mitochondrial transfer RNA molecules, leading to impaired energy production. E88.43 sits in the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89), within the section covering metabolic disorders (e70-e88).
Under the older CMS-HCC V24 model, E88.43 maps to Other Significant Endocrine and Metabolic Disorders (HCC 23) with a community, non-dual, aged base RAF weight of 0.194. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.
Document which specific tRNA synthetase is affected if known (e.g., DARS2, AARS2). Because E88.43 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for E88.43 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Document which specific tRNA synthetase is affected if known (e.g., DARS2, AARS2)
- •These disorders typically present with progressive neurological symptoms; coordinate coding with neurological manifestation codes
Clinical Significance
Disorders of mitochondrial tRNA synthetases are rare genetic conditions affecting the enzymes that attach amino acids to transfer RNA within mitochondria, impairing protein synthesis in mitochondria. These disorders cause varied multi-system phenotypes depending on the specific enzyme affected.
Documentation Requirements
- ✓Confirmed diagnosis of a mitochondrial tRNA synthetase disorder
- ✓Specific enzyme/gene identified if known (DARS2, EARS2, RARS2, etc.)
- ✓Genetic testing results confirming the diagnosis
- ✓Affected organ systems and functional impact
- ✓Clinical manifestations documented (leukoencephalopathy, cardiomyopathy, sensorineural hearing loss)
- ✓Treatment and management plan
Code Also
- , if applicable, associated condition such as:
- leukoencephalopathy (G93.49)
Commonly Confused Codes
- •E88.40 — Mitochondrial metabolism disorder, unspecified: less specific; use E88.43 when tRNA synthetase disorder is confirmed
- •E88.41 — MELAS syndrome: different type of mitochondrial disorder
- •E88.42 — MERRF syndrome: different type of mitochondrial disorder
- •E88.49 — Other mitochondrial metabolism disorders: for other specified mitochondrial disorders not in E88.41-E88.43