E08.00
BillableDiabetes mellitus due to underlying condition with hyperosmolarity without nonketotic hyperglycemic-hyperosmolar coma (NKHHC)
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is E08.00 an HCC code?
Yes. E08.00 maps to Diabetes with Acute Complications under the CMS-HCC V28 risk adjustment model (and Diabetes with Acute Complications 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 E08.00
For E08.00 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 E08.00 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
E08.00 is the ICD-10-CM diagnosis code for diabetes mellitus due to underlying condition with hyperosmolarity without nonketotic hyperglycemic-hyperosmolar coma (nkhhc). High blood sugar caused by an underlying medical condition with dangerously concentrated blood without a life-threatening coma. E08.00 sits in the ICD-10-CM chapter for endocrine, nutritional and metabolic diseases (e00-e89), within the section covering diabetes mellitus (e08-e13).
Under the CMS-HCC V28 risk adjustment model, E08.00 maps to Diabetes with Acute Complications (HCC 36) with a community, non-dual, aged base RAF weight of 0.390. Under the older V24 model, E08.00 mapped to the same category but with a base RAF weight of 0.302 — V28 recalibrated weights across the entire model. 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.
Verify the underlying condition causing the diabetes is documented and coded separately. Because E08.00 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 E08.00 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Verify the underlying condition causing the diabetes is documented and coded separately
- •Confirm hyperosmolarity is present without coma to distinguish from E08.01
Clinical Significance
Diabetes mellitus due to an underlying condition with hyperosmolarity without nonketotic hyperglycemic-hyperosmolar coma (NKHHC) represents a serious acute metabolic complication of secondary diabetes where severe hyperglycemia causes profound dehydration and hyperosmolarity. The underlying conditions causing this diabetes category include pancreatitis, cystic fibrosis, hemochromatosis, Cushing syndrome, and other diseases that impair insulin secretion or action. This condition carries significant morbidity with mortality rates of 5-20% even with treatment.
Documentation Requirements
- ✓Document the underlying condition causing diabetes, the hyperosmolar state with serum osmolality and glucose levels, absence of coma, and the causal relationship between the underlying condition and diabetes.
- ✓Code the underlying condition first, followed by this diabetes code.
- ✓Record fluid resuscitation and insulin therapy details.
Commonly Confused Codes
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