ICDcodes.org
FY2027

D56 vs D57

D56 and D57 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
sickle-cell thalassemia (D57.4-)
D56

Thalassemia

Not billable
Chapter 3
Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism
Section
D55-D59
D57

Sickle-cell disorders

Not billable
Chapter 3
Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism
Section
D55-D59
Indexed under
  • Arthropathy › gouty › in › sickle-cell disorders

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