D56.0 Alpha thalassemia

✓ Billable ICD-10-CM 2026
Open D56.0 in Web App →

The ICD-10-CM code for Alpha thalassemia is D56.0 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Section
D55-D59: Hemolytic anemias (D55-D59)
Category D56
9 codes (8 billable)
FY2026 Status
Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to D56.0:

  • Hb (abnormal) › Bart's disease
  • Thalassemia (anemia) (disease) › alpha (major) (severe) (triple gene defect)
  • Hemoglobin › H Constant Spring
  • Disease, diseased › hemoglobin or Hb › Bart's
  • Disease, diseased › hemoglobin or Hb › H (Hb-H) (thalassemia)
  • Hydrops › newborn (idiopathic) › due to › alpha thalassemia
  • Disease, diseased › hemoglobin or Hb › H (Hb-H) (thalassemia) › Constant Spring
  • Hydrops › fetalis › due to › alpha thalassemia
Excludes1
Not coded here. These conditions should NOT be coded together with D56.0.
  • alpha thalassemia trait or minor (D56.3)
  • asymptomatic alpha thalassemia (D56.3)
  • hydrops fetalis due to isoimmunization (P56.0)
  • hydrops fetalis not due to immune hemolysis (P83.2)
Use Additional Code
  • code, if applicable, for hydrops fetalis due to alpha thalassemia (P56.99)

Inclusion Terms

  • Alpha thalassemia major
  • Hemoglobin H Constant Spring
  • Hemoglobin H disease
  • Hydrops fetalis due to alpha thalassemia
  • Severe alpha thalassemia
  • Triple gene defect alpha thalassemia

U.S. Hospital Utilization

  • An estimated 4,795 U.S. inpatient stays in 2023 included D56.0 among the documented diagnoses.
  • 80 stays listed it as the principal diagnosis.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

Official Coding Guidelines

Chapter 3 TOC entry

3. Chapter 3: Disease of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89) ............................................................................................. 39

— ICD-10-CM Official Guidelines for Coding and Reporting, FY2026, Section I.C.3
Reserved for future guideline expansion

Reserved for future guideline expansion ...................................................................................... 39

— ICD-10-CM Official Guidelines for Coding and Reporting, FY2026, Section I.C.3.Reserved

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

Related Codes

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Reviewed by Prajwal Shrestha, CPC, CRC
Certified Professional Coder (CPC) and Certified Risk Adjustment Coder (CRC) · AAPC Member ID 01997614 · About · Editorial policy · Content last reviewed: 2025-10-01

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