Excludes1 pair
D56.0 vs D56.3
D56.0 and D56.3 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 D56.0
alpha thalassemia trait or minor (D56.3)
D56.0
Alpha 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
- Alpha thalassemia major
- Hemoglobin H Constant Spring
- Hemoglobin H disease
- Hydrops fetalis due to alpha thalassemia
- Severe alpha thalassemia
- Triple gene defect alpha thalassemia
Indexed under
- 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)
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
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