D56.0 vs P56.0
D56.0 (Alpha thalassemia) compared with P56.0 (Hydrops fetalis due to isoimmunization), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. D56.0 carries an Excludes1 note covering P56.0: “hydrops fetalis due to isoimmunization (P56.0)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Side by side
| D56.0Alpha thalassemia | P56.0Hydrops fetalis due to isoimmunization | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | D50-D89 — Diseases of the Blood and Blood-forming Organs and Certain Disorders Involving the Immune Mechanism (D50-D89) | P00-P96 — Certain Conditions Originating in the Perinatal Period (P00-P96) |
| Definition | Alpha thalassemia is a billable ICD-10-CM diagnosis code (D56.0). | Hydrops fetalis due to isoimmunization is a billable ICD-10-CM diagnosis code (P56.0). |
| Includes | Alpha thalassemia major Hemoglobin H Constant Spring Hemoglobin H disease Hydrops fetalis due to alpha thalassemia | — |
| Use additional code | code, if applicable, for hydrops fetalis due to alpha thalassemia (P56.99) | — |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources