D57.412
BillableSickle-cell thalassemia, unspecified, with splenic sequestration
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is D57.412 an HCC code?
Yes. D57.412 maps to Sickle Cell Disorders and Thalassemia 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 D57.412
For D57.412 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 D57.412 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
D57.412 is the ICD-10-CM diagnosis code for sickle-cell thalassemia, unspecified, with splenic sequestration. This is a blood disorder where a person has both sickle-cell disease and thalassemia (two inherited conditions affecting red blood cells), and their spleen has become enlarged and is trapping blood cells, which can cause serious complications. This specific code is used when the exact type of sickle-cell thalassemia is not specified. D57.412 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 hemolytic anemias (d55-d59).
Under the CMS-HCC V28 risk adjustment model, D57.412 maps to Sickle Cell Disorders and Thalassemia (HCC 108) with a community, non-dual, aged base RAF weight of 0.607. Under the older CMS-HCC V24 model, D57.412 maps to Severe Hematological Disorders (HCC 46) with a community, non-dual, aged base RAF weight of 0.666. 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 documentation specifies splenic sequestration as a complication; if only sickle-cell thalassemia is documented without this complication, use a different D57.4 code. Because D57.412 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 D57.412 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Verify documentation specifies splenic sequestration as a complication; if only sickle-cell thalassemia is documented without this complication, use a different D57.4 code
- •This code requires a 5th character; ensure the 5th digit (2) is included to indicate 'unspecified' type, and confirm no additional specificity (such as HbSC or HbSD disease) is documented that would require a more specific code
Clinical Significance
Splenic sequestration in unspecified sickle-cell thalassemia is an acute crisis where the spleen traps large volumes of blood, causing rapid anemia and potentially hemodynamic instability. Sickle-cell thalassemia patients, particularly beta-plus variants, may retain splenic function longer than Hemoglobin SS patients, maintaining the risk of sequestration into adulthood. The thalassemia component (beta-zero vs. beta-plus) is unspecified, representing a documentation opportunity.
Documentation Requirements
- ✓Documentation must confirm the sickle-cell thalassemia genotype and acute splenic sequestration with evidence of rapid splenic enlargement and hemoglobin decline.
- ✓Query for beta-zero vs.
- ✓beta-plus specification.
- ✓Record splenic size, hemoglobin trend, reticulocyte count, platelet count, treatment including transfusion, and whether splenectomy is recommended.
- ✓Note splenic function status (functional vs.
- ✓autosplenectomized).