D56.1 vs D56.3
D56.1 and D56.3 can never be reported together. ICD-10-CM declares them mutually exclusive with an Excludes1 note, meaning the two conditions cannot occur in the same patient — so exactly one of them is correct for any given encounter.
The official note, declared on D56.1
beta thalassemia minor (D56.3)
D56.1
Beta thalassemia
Billable
- Chapter 3
- Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism
- Section
- D55-D59
Use when the record says
- Beta thalassemia major
- Cooley's anemia
- Homozygous beta thalassemia
- Severe beta thalassemia
- Thalassemia intermedia
- Thalassemia major
Indexed under
- Cooley's anemia
- Anemia › Cooley's (essential) (general) (hemoglobin deficiency) (infantile) (primary) (profound)
- Anemia › familial erythroblastic (essential) (general) (hemoglobin deficiency) (infantile) (primary) (profound)
- Thalassemia › beta (anemia) (disease)
- Thalassemia › intermedia (anemia) (disease)
D56.3
Thalassemia minor
Billable
- Chapter 3
- Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism
- Section
- D55-D59
Use when the record says
- Alpha thalassemia minor
- Alpha thalassemia silent carrier
- Alpha thalassemia trait
- Beta thalassemia minor
- Beta thalassemia trait
- Delta-beta thalassemia minor
- Delta-beta thalassemia trait
- Thalassemia trait NOS
Indexed under
- Thalassemia › minor (anemia) (disease)
- Thalassemia › trait (anemia) (disease)
- Trait › Lepore (s)
- Thalassemia › alpha › minor (anemia) (disease)
- Thalassemia › alpha › silent carrier (anemia) (disease)
Excludes1 is not always absolute: where two conditions covered by the note are genuinely unrelated, CMS guidance permits reporting both. Document the reasoning rather than assuming it. More on Excludes1 vs Excludes2 · FY2027