ICD-10 Code D71 – Functional disorders of polymorphonuclear neutrophils (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D71 – Functional disorders of polymorphonuclear neutrophils
What it is
D71 identifies disorders where polymorphonuclear neutrophils do not function properly. These cells are part of the immune response, so impaired activity can reduce the body’s ability to fight certain infections.
Clinical signs
Clinical features vary; refer to documentation. Commonly, records note recurrent or unusual infections, poor inflammatory response, or a known neutrophil functional defect confirmed by specialist evaluation.
When to use this code
Use D71 when the provider documents a functional neutrophil disorder, such as an inherited or acquired defect affecting neutrophil activity. Code it when the diagnosis is established or clearly stated in the chart. Do not infer it from infection alone; check documentation.
Do not use for
Do not use D71 for neutropenia, agranulocytosis, or other cell-count abnormalities without a functional defect. If the note only describes infection risk or an unspecified immune problem, check documentation.
Coding tip
Assign D71 only when the record supports impaired neutrophil function, not merely abnormal white blood cell counts.