Excludes1 pair

D56.3 vs D56.5

D56.3 and D56.5 are not coded together. ICD-10-CM declares them mutually exclusive with an Excludes1 note — the two conditions are not expected to occur together, so exactly one of them is normally correct for a given encounter. The Official Guidelines carve out one exception: if the two conditions are clearly unrelated to each other, both may be reported.

The official note, declared on D56.3
hemoglobin E-beta thalassemia (D56.5)
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
  • Thalassemia › trait
  • Trait › Lepore
  • Thalassemia › alpha › minor
  • Thalassemia › alpha › silent carrier
D56.5

Hemoglobin E-beta thalassemia

Billable
Chapter 3
Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism
Section
D55-D59
Indexed under
  • Hemoglobin › E-beta thalassemia
  • Disease, diseased › hemoglobin or Hb › E-beta thalassemia
  • Thalassemia › hemoglobin › E-beta

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