D56.0 — Alpha thalassemia
D56.0 is a billable, specific ICD-10-CM code for alpha thalassemia. It is valid for submission on a claim.
Excludes1 — never code together
These conditions cannot occur together. Billing both on the same encounter is a denial.
Use additional code
Add a secondary code to capture the detail described below.
- code, if applicable, for hydrops fetalis due to alpha thalassemia (P56.99)
Inclusion terms
Alternative wordings a physician may use in the chart for this same code.
- Alpha thalassemia major
- Hemoglobin H Constant Spring
- Hemoglobin H disease
- Hydrops fetalis due to alpha thalassemia
- Severe alpha thalassemia
- Triple gene defect alpha thalassemia
Other codes that can never be billed with D56.0
These codes carry an Excludes1 note pointing at D56.0. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading D56.0 alone.
- D56.3Thalassemia minor
Risk adjustment
D56.0 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.
Medicare coverage
D56.0 is named in 10 Medicare coverage policies — 10 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A55717Billing and Coding: Lab: Flow Cytometry
- A56464Billing and Coding: Flow Cytometry
- A56580Billing and Coding: Computerized Axial Tomography (CT), Thorax
- A56697Billing and Coding: Non-Invasive Vascular Studies
How D56.0 is indexed
Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to D56.0.
- Hb›Bart's disease
- Hemoglobin›H Constant Spring
- Thalassemia›alpha(major) (severe) (triple gene defect)
- Disease, diseased›hemoglobin or Hb›Bart's
- Disease, diseased›hemoglobin or Hb›H(Hb-H) (thalassemia)
- Disease, diseased›hemoglobin or Hb›H›Constant Spring
- Hydrops›fetalis›due to›alpha thalassemia
- Hydrops›newborn›due to›alpha thalassemia
Related codes at this level
Codes that share D56. If D56.0 is not quite right, the correct code is usually one of these.
Questions about D56.0
- Is D56.0 a billable ICD-10-CM code?
- Yes. D56.0 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does D56.0 sit in the tabular list?
- Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89), in the block Hemolytic anemias (D55-D59).
- What cannot be coded together with D56.0?
- D56.0 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.