ICD-10 Code D56.4 – Hereditary persistence of fetal hemoglobin [HPFH] (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D56.4 – Hereditary persistence of fetal hemoglobin [HPFH]
What it is
Hereditary persistence of fetal hemoglobin (HPFH) is an inherited condition in which fetal hemoglobin remains present beyond infancy. It is usually benign and may be found incidentally during hemoglobin testing.
Clinical signs
Clinical features vary; refer to documentation. Many patients have no symptoms, while others may show elevated fetal hemoglobin on hemoglobin studies and a family history of the trait.
When to use this code
Use D56.4 when the provider documents HPFH or hereditary persistence of fetal hemoglobin as the diagnosis. It also applies when the record clearly identifies the condition during evaluation of an abnormal hemoglobin pattern. Do not use it for unspecified anemia without documentation of HPFH.
Do not use for
Do not use this code for other hemoglobinopathies, thalassemias, or sickle cell disorders unless HPFH is specifically documented. Check documentation if the record only mentions elevated fetal hemoglobin without a named hereditary condition.
Coding tip
Code the documented hereditary condition, not the lab finding alone, unless the provider explicitly links the result to HPFH.