D56.2 ICD-10-CM Code: Delta-beta thalassemia
D56.2 maps to CMS-HCC V28 108. A source-labeled RAF reference is available. Confirm the documented diagnosis and applicable coding requirements. MEAT criteria · RAF Calculator · HCC coding software
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FY 2026 Apr update / Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89) / Hemolytic anemias (D55-D59)
D56.2
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceDelta-beta thalassemia
Delta-beta thalassemia is a rare inherited blood disorder where the body doesn't make enough hemoglobin, a protein in red blood cells that carries oxygen. This condition affects the production of two types of hemoglobin chains (delta and beta), leading to anemia and related complications.
Buddy Insight
Delta-beta thalassemia is a rare inherited hemoglobin disorder caused by deletions affecting both the delta and beta globin genes, resulting in reduced production of both hemoglobin A and hemoglobin A2 with compensatory elevation of fetal hemoglobin.
CMS-HCC V28
MappedHCC 108
Coefficient HCC 108: 0.146 (Community Non-Dual Aged (CNA))
CMS-HCC V24
HistoricalHistorical
Not used for CY2026 payment
ACA/HHS
MappedHCC 071
Code-level coefficient reference
ESRD/PACE
MappedHCC 48
Code-level coefficient reference
RXHCC
N/A—
Not mapped
Code Book Path
Inclusion Terms
Official- Homozygous delta-beta thalassemia
Excludes 2
Official- autoimmune disease (systemic) NOS (M35.9)Inherited from D50-D89
- certain conditions originating in the perinatal period (P00-P96)Inherited from D50-D89
- complications of pregnancy, childbirth and the puerperium (O00-O9A)Inherited from D50-D89
- congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)Inherited from D50-D89
- endocrine, nutritional and metabolic diseases (E00-E88)Inherited from D50-D89
- human immunodeficiency virus [HIV] disease (B20)Inherited from D50-D89
- injury, poisoning and certain other consequences of external causes (S00-T88)Inherited from D50-D89
- neoplasms (C00-D49)Inherited from D50-D89
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)Inherited from D50-D89
Related Codes
Includes
OfficialNo Includes notes are included in this display for D56.2. Check the code and parent instructions in the Code Book.
Excludes 1
Official- delta-beta thalassemia minor (D56.3)
- delta-beta thalassemia trait (D56.3)
- sickle-cell thalassemia (D57.4-)Inherited from D56
Code First
OfficialNo Code First sequencing instructions are included in this display for D56.2. Check the code and parent instructions in the Code Book.
Use Additional
OfficialNo Use Additional Code instructions are included in this display for D56.2. Check the code and parent instructions in the Code Book.
Code Also
OfficialNo Code Also instructions are included in this display for D56.2. Check the code and parent instructions in the Code Book.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →
Is D56.2 an HCC code?
Yes. D56.2 (Delta-beta thalassemia) maps to HCC 108, Sickle Cell Disorders, Except Sickle Cell Anemia (Hb-SS) and Thalassemia Beta Zero; Beta Thalassemia Major under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 0.146. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes. It is billable for payment year 2026.
Coder answer: D56.2 is billable and maps to V28 HCC 108, Sickle Cell Disorders, Except Sickle Cell Anemia (Hb-SS) and Thalassemia Beta Zero; Beta Thalassemia Major. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.
- Code
- D56.2
- Description
- Delta-beta thalassemia
- HCC (V28)
- HCC 108 — Sickle Cell Disorders, Except Sickle Cell Anemia (Hb-SS) and Thalassemia Beta Zero; Beta Thalassemia Major
- RAF reference coefficient
- 0.146
- Billable
- Yes
- Payment year
- 2026
HCC Category Mapping
These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. Weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.
Work D56.2 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →
MEAT review for D56.2
For D56.2, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.
- 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
Coder workflow notes
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What This Code Means
D56.2 is the ICD-10-CM diagnosis code for delta-beta thalassemia. Delta-beta thalassemia is a rare inherited blood disorder where the body doesn't make enough hemoglobin, a protein in red blood cells that carries oxygen. This condition affects the production of two types of hemoglobin chains (delta and beta), leading to anemia and related complications. D56.2 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, D56.2 maps to Sickle Cell Disorders, Except Sickle Cell Anemia (Hb-SS) and Thalassemia Beta Zero; Beta Thalassemia Major (HCC 108) with a source-labeled community, non-dual, aged reference coefficient of 0.146. For CY2026 non-PACE Medicare Advantage, CMS uses 100% of the 2024 CMS-HCC model (V28). PACE uses a separate model blend. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes.
Verify the specific type of thalassemia documented in the medical record, as D56.2 is specifically for delta-beta thalassemia and should not be confused with other thalassemia variants (D56.0, D56.1, D56.3, D56.4, D56.5, or D56.8). For D56.2, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule. 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, source-labeled coefficient references, and MEAT documentation criteria for D56.2 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 thalassemia documented in the medical record, as D56.2 is specifically for delta-beta thalassemia and should not be confused with other thalassemia variants (D56.0, D56.1, D56.3, D56.4, D56.5, or D56.8)
- •Document any complications such as hemolytic anemia, splenomegaly, or transfusion dependence separately, as these may require additional codes to fully capture the clinical picture and severity
Clinical Significance
Delta-beta thalassemia is a rare inherited hemoglobin disorder caused by deletions affecting both the delta and beta globin genes, resulting in reduced production of both hemoglobin A and hemoglobin A2 with compensatory elevation of fetal hemoglobin. Clinical presentation is generally milder than beta thalassemia major, often resembling thalassemia intermedia with moderate anemia. The elevated fetal hemoglobin provides some clinical benefit by partially compensating for reduced adult hemoglobin production.
Documentation Requirements
- ✓Documentation must confirm delta-beta thalassemia specifically through hemoglobin electrophoresis showing elevated fetal hemoglobin with reduced hemoglobin A and A2, and ideally molecular genetic testing confirming the delta-beta deletion.
- ✓Record hemoglobin levels, mean corpuscular volume, reticulocyte counts, transfusion requirements if any, and complications.
- ✓Distinguish clearly from beta thalassemia and hereditary persistence of fetal hemoglobin.
Excludes 1, Do NOT code together
Commonly Confused Codes
- •D56.2 vs. D56.1 (Beta thalassemia) -
- •delta-beta thalassemia affects both delta and beta genes versus beta alone. D56.2 vs. D56.4 (Hereditary persistence of fetal hemoglobin) -
- •both have elevated fetal hemoglobin, but hereditary persistence of fetal hemoglobin is typically asymptomatic with higher fetal hemoglobin levels and balanced globin chain production. D56.2 vs. D56.8 (Other thalassemias) -
- •use D56.2 when the specific delta-beta deletion is confirmed.