E88.89
BillableOther specified metabolic disorders
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is E88.89 an HCC code?
Yes. E88.89 maps to Glycogen/Amino-Acid/Other Metabolic Disorders under the CMS-HCC V28 risk adjustment model (and Other Significant Endocrine and Metabolic Disorders under V24).
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 E88.89
For E88.89 to 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 E88.89 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
E88.89 is the ICD-10-CM diagnosis code for other specified metabolic disorders. Other specified metabolic disorders affecting how the body processes nutrients and produces energy, not classified in other categories. E88.89 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 CMS-HCC V28 risk adjustment model, E88.89 maps to Glycogen/Amino-Acid/Other Metabolic Disorders (HCC 50) with a community, non-dual, aged base RAF weight of 0.289. Under the older CMS-HCC V24 model, E88.89 maps to Other Significant Endocrine and Metabolic Disorders (HCC 23) with a community, non-dual, aged base RAF weight of 0.230. 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.
Use this code for documented metabolic disorders that don't fit into the more specific E88 subcategories. Because E88.89 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 E88.89 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use this code for documented metabolic disorders that don't fit into the more specific E88 subcategories
- •Always specify the exact metabolic disorder in the medical record to support the diagnosis and allow for future code specificity
Clinical Significance
Other specified metabolic disorders is a broad catch-all for metabolic conditions not classified elsewhere. This may include rare inborn errors of metabolism, metabolic syndrome (when not coded separately), histiocytosis syndromes, and other specified metabolic derangements requiring ongoing management.
Documentation Requirements
- ✓Specific metabolic disorder identified by the provider
- ✓Clinical or laboratory evidence supporting the metabolic diagnosis
- ✓Description of how the condition affects the patient's health
- ✓Treatment and management plan
- ✓Documentation that no more specific ICD-10-CM code exists for the condition
Excludes 1 — Do NOT code together
- adult pulmonary Langerhans cell histiocytosis (J84.82)
Commonly Confused Codes
- •E88.9 — Metabolic disorder, unspecified: even less specific and does NOT carry HCC mapping
- •E88.01 — Alpha-1-antitrypsin deficiency: has its own specific code with HCC mapping
- •E88.40-E88.49 — Mitochondrial metabolism disorders: have their own code category
- •E79.0 — Hyperuricemia: specific metabolic condition with its own code