D64.4
BillableCongenital dyserythropoietic anemia
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is D64.4 an HCC code?
Yes. D64.4 maps to Hemolytic and Aplastic Anemias under the CMS-HCC V28 risk adjustment model.
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 D64.4
For D64.4 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 D64.4 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
D64.4 is the ICD-10-CM diagnosis code for congenital dyserythropoietic anemia. A rare inherited disorder where the bone marrow produces abnormally shaped red blood cells from birth. D64.4 sits in the ICD-10-CM chapter for diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (d50-d89), within the section covering aplastic and other anemias and other bone marrow failure syndromes (d60-d64).
Under the CMS-HCC V28 risk adjustment model, D64.4 maps to Hemolytic and Aplastic Anemias (HCC 109) with a community, non-dual, aged base RAF weight of 0.291. D64.4 was not retained as a payment HCC under the older V24 model, so V28 introduced or recategorized it during the 2024–2026 phase-in. 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.
This is a congenital condition; document family history when available. Because D64.4 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 D64.4 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This is a congenital condition; document family history when available
- •Distinguish from acquired sideroblastic anemias which have different codes
Clinical Significance
Congenital dyserythropoietic anemia is a rare inherited bone marrow disorder characterized by ineffective erythropoiesis and distinct morphological abnormalities of erythroblasts. It leads to chronic anemia, iron overload, and potential secondary hemochromatosis requiring lifelong monitoring. This condition maps to HCC 109 (V28, RAF 0.291), reflecting its chronic resource utilization.
Documentation Requirements
- ✓Document the specific type of congenital dyserythropoietic anemia (Type I, II, or III) when known, along with genetic confirmation or bone marrow biopsy findings.
- ✓Record baseline hemoglobin levels, transfusion history, iron studies (ferritin, transferrin saturation), and any evidence of iron overload complications such as hepatic or cardiac involvement.