D57.01
BillableHb-SS disease with acute chest syndrome
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is D57.01 an HCC code?
Yes. D57.01 maps to Sickle Cell Anemia (Hb-SS) and Thalassemia Beta Zero 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 D57.01
For D57.01 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 D57.01 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
D57.01 is the ICD-10-CM diagnosis code for hb-ss disease with acute chest syndrome. This is a serious complication of sickle cell disease where a person with two copies of the sickle cell gene (HbSS) develops sudden chest pain, difficulty breathing, and lung inflammation. It's a medical emergency that requires immediate hospitalization and treatment. D57.01 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, D57.01 maps to Sickle Cell Anemia (Hb-SS) and Thalassemia Beta Zero (HCC 107) with a community, non-dual, aged base RAF weight of 0.727. Under the older CMS-HCC V24 model, D57.01 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.
Acute chest syndrome must be documented by the physician as a current condition during the encounter; do not assume it from lab values or imaging alone. Because D57.01 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 D57.01 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Acute chest syndrome must be documented by the physician as a current condition during the encounter; do not assume it from lab values or imaging alone
- •This code includes the sickle cell disease diagnosis, so do not separately code D57.00 (HbSS disease without crisis) when acute chest syndrome is present
Clinical Significance
Acute chest syndrome in Hemoglobin SS disease is a life-threatening complication characterized by new pulmonary infiltrate on chest imaging with respiratory symptoms including chest pain, fever, cough, or hypoxia. It is the leading cause of death and the second most common cause of hospitalization in sickle cell disease. The pathophysiology involves vaso-occlusion in pulmonary vasculature, fat embolism from bone marrow infarction, and infection, often requiring intensive care management.
Documentation Requirements
- ✓Documentation must include the Hemoglobin SS genotype, clinical presentation with respiratory symptoms (chest pain, dyspnea, cough, fever, hypoxia), chest imaging confirming new pulmonary infiltrate, and the provider's explicit diagnosis of acute chest syndrome.
- ✓Record oxygen saturation, arterial blood gas results, treatment administered (exchange transfusion, antibiotics, supplemental oxygen, bronchodilators), and clinical course.
- ✓Do not rely solely on lab values or imaging to assign this code.