D46.4
BillableRefractory anemia, unspecified
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is D46.4 an HCC code?
Yes. D46.4 maps to Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers under the CMS-HCC V28 risk adjustment model (and Severe Hematological 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 D46.4
For D46.4to 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 D46.4 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
D46.4 is the ICD-10-CM diagnosis code for refractory anemia, unspecified. This code describes a type of anemia where the bone marrow is not producing enough healthy red blood cells and the condition does not respond well to standard treatment. It is a blood disorder that can lead to fatigue and other complications if left untreated. D46.4 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering neoplasms of uncertain behavior, polycythemia vera and myelodysplastic syndromes (d37-d48).
Under the CMS-HCC V28 risk adjustment model, D46.4 maps to Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers (HCC 19) with a community, non-dual, aged base RAF weight of 1.798. Under the older CMS-HCC V24 model, D46.4 maps to Severe Hematological Disorders (HCC 46) with a community, non-dual, aged base RAF weight of 1.372. 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 specific type of refractory anemia in the medical record; if documented as refractory anemia with excess blasts, ring sideroblasts, or multilineage dysplasia, use the more specific D46 subcategories instead of D46.4. Because D46.4 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 D46.4 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Verify the specific type of refractory anemia in the medical record; if documented as refractory anemia with excess blasts, ring sideroblasts, or multilineage dysplasia, use the more specific D46 subcategories instead of D46.4
- •Ensure the provider has documented that standard anemia treatments (such as iron supplementation or B12 therapy) have been ineffective before coding as 'refractory' to support medical necessity
Clinical Significance
Refractory anemia, unspecified, represents a myelodysplastic syndrome where the bone marrow fails to produce adequate red blood cells and standard anemia therapies are ineffective, but the specific subtype has not been determined. This code indicates a need for further workup to classify the specific myelodysplastic syndrome subtype for optimal prognostication and treatment planning.
Documentation Requirements
- ✓Use this code when documentation confirms refractory anemia as part of a myelodysplastic process but does not specify the subtype.
- ✓A provider query should be initiated to obtain bone marrow biopsy results including blast percentage, ring sideroblast status, and cytogenetic findings.
- ✓Document transfusion requirements and response to prior anemia treatments.
Commonly Confused Codes
- •D46.0 through D46.B are specific myelodysplastic syndrome subtypes and should be used when documentation permits.
- •D64.9 (anemia, unspecified) is for non-myelodysplastic anemias.
- •D63.1 (anemia in chronic kidney disease) and D63.0 (anemia in neoplastic disease) are specific secondary anemias that should not be confused with refractory anemia.