2027 ICD-10-CM Diagnosis Code D56.0Alpha thalassemia

ICD-10-CM Codes›D50–D89›D55-D59›D56

ICD-10-CM D56.0
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

D56.0 is a billable ICD-10-CM diagnosis code for alpha thalassemia. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 791, 793, 811 through 812. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Hemolytic anemia.

D56.0 no longer risk-adjusts for Medicare Advantage: it mapped to HCC 48 under the retired CMS-HCC V24 model through payment year 2025 but maps to no category in the live V28 model. It still risk-adjusts in the PACE (CMS-HCC V22) category 48, ESRD (V21) category 48, and ESRD (V24) category 48 for payment year 2027.

Code Identity

ICD-10-CM Code
D56.0
Billable Status
Yes — Valid for Submission
Code Describes
Alpha thalassemia
Short Description
Alpha thalassemia
Same as the full description in the CMS dataset.
Parent Code
D56
Thalassemia

Code Classification

ChapterD50–D89Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism
SectionD55-D59Hemolytic anemias
CategoryD56Thalassemia
This CodeD56.0Alpha thalassemia

Medicare Risk Adjustment (HCC)Billing

D56.0 no longer risk-adjusts for Medicare Advantage: it maps to no payment category in the live CMS-HCC V28 model, although it still risk-adjusts in the other CMS models shown below.

CMS-HCC V28 (Medicare Advantage Payment Model)
Not mapped
Dropped in V28 see all codes that no longer risk-adjust
Prior Model (CMS-HCC V24)
HCC 48
V24 retired last contributed to a Medicare Advantage risk score in payment year 2025
Other CMS Models
PACE (CMS-HCC V22): HCC 48 · ESRD (V21): HCC 48 · ESRD (V24): HCC 48
ESRD V21 weights: 0.059 dialysis, 0.173–0.234 functioning graft · ESRD V24 weights: 0.063 dialysis, 0.192–0.358 functioning graft
Part D (RxHCC)
Not mapped
D56.0 does not risk-adjust in the RxHCC prescription drug model

Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acquired hemoglobin H disease
  • Alpha plus thalassemia
  • Alpha plus thalassemia deletion type
  • Alpha plus thalassemia non deletion type
  • Alpha thalassemia
  • Alpha thalassemia X-linked intellectual disability syndrome
  • Alpha zero thalassemia
  • Alpha-thalassemia intellectual disability syndrome linked to chromosome 16
  • Deletion of part of short arm of chromosome 16
  • Fetal anemia
  • Fetal hereditary disease
  • Hemoglobin Bart's hydrops syndrome
  • Hemoglobin H constant spring thalassemia
  • Hemoglobin H disease
  • Hemoglobin Paksé disease
  • Hemoglobin Seal Rock disease
  • Homozygous alpha thalassemia
  • Hydrops fetalis
  • Sickle cell anemia with coexistent alpha-thalassemia
  • Sickle cell-hemoglobin SS disease
  • Sickle cell-thalassemia disease

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to D56.0: its own notes plus those printed at D56 and Chapter 3. A note printed at a category, block or chapter applies to every code under it.

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

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

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

On D56.0 itself
  • 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)
From D56 Thalassemia applies to 8 codes
  • sickle-cell thalassemia (D57.4-)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 3 (D50-D89) Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism applies to 324 codes
  • autoimmune disease (systemic) NOS (M35.9)
  • certain conditions originating in the perinatal period (P00-P96)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • human immunodeficiency virus [HIV] disease (B20)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

  • code, if applicable, for hydrops fetalis due to alpha thalassemia (P56.99)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name D56.0, its category, or a range that includes it.

Excludes1 2

These codes carry an Excludes1 note naming D56.0: they are not reported together with it, unless the two conditions are unrelated.

  • D56.3 Thalassemia minor
    alpha thalassemia (D56.0)
  • Block P50-P61 Hemorrhagic and hematological disorders of newborn
    hereditary hemolytic anemias (D55-D58) names D55-D58, which includes this code

Code First 1

These codes say to code first a condition named in the note, and D56.0 is one of the conditions named.

  • M36.3 Arthropathy in other blood disorders
    thalassemia (D56.-) names D56.-, which includes this code

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR BLD002
Hemolytic anemia
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • alpha-Thalassemia

    a disorder characterized by reduced synthesis of the alpha chains of hemoglobin. the severity of this condition can vary from mild anemia to death, depending on the number of genes deleted.

Patient EducationClinical

Thalassemia

Thalassemias are inherited blood disorders. If you have one, your body makes fewer healthy red blood cells and less hemoglobin. Hemoglobin is a protein that carries oxygen to the body. That leads to anemia. Thalassemias occur most often among people of Italian, Greek, Middle Eastern, Southern Asian, and African descent.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert D56.0 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
282.43 Alpha thalassemia
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About D56.0Overview

What is the ICD-10 code for alpha thalassemia?

The ICD-10-CM code for alpha thalassemia is D56.0 (sometimes written as D560). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is D56.0 (Thalassemia) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report alpha thalassemia on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does D56.0 group to?

When alpha thalassemia is the principal diagnosis on an inpatient stay, it groups to MS-DRG 793, 791, 812, 811, with relative weights from 0.9237 to 4.2192 depending on complications. Higher weights mean higher Medicare reimbursement.

Can D56.0 be reported with D56.3?

Not as a rule. The Excludes1 note on D56.0 lists "alpha thalassemia trait or minor (D56.3)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

Does D56.0 need an additional code?

When the condition applies, yes. The Use Additional Code note reads: code, if applicable, for hydrops fetalis due to alpha thalassemia (P56.99). The additional code is reported after D56.0.

Does D56.0 risk-adjust for Medicare Advantage payment?

Not for Medicare Advantage. D56.0 mapped to HCC 48 in the retired CMS-HCC V24 model, which last determined payment in 2025, but it maps to no category in the live V28 model; see all codes that no longer risk-adjust. It still risk-adjusts in the PACE (CMS-HCC V22) category 48 (Coagulation Defects and Other Specified Hematological Disorders), ESRD (V21) category 48 (Coagulation Defects and Other Specified Hematological Disorders), and ESRD (V24) category 48 (Coagulation Defects and Other Specified Hematological Disorders).