ICD-10 Code D71.9 – Functional disorders of polymorphonuclear neutrophils, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D71.9 – Functional disorders of polymorphonuclear neutrophils, unspecified
What it is
D71.9 identifies an unspecified disorder affecting the normal function of polymorphonuclear neutrophils, the white blood cells that help fight infection. Use it when the record documents a neutrophil function problem but does not name a specific disorder.
Clinical signs
Clinical features vary; refer to documentation. Commonly, these disorders are associated with recurrent or unusual infections and impaired neutrophil function, but the exact presentation depends on the underlying condition.
When to use this code
Use D71.9 when the clinician documents a functional neutrophil disorder and does not specify a more precise diagnosis. It also fits cases where the chart notes abnormal neutrophil function, but the subtype is not stated. Check documentation if the record names a defined inherited disorder.
Do not use for
Do not use this code for neutropenia, other white blood cell disorders, or a clearly identified neutrophil defect with a more specific ICD-10-CM code. If the condition is described differently, verify the exact diagnosis.
Coding tip
Query for the exact neutrophil disorder name before assigning D71.9, because a more specific code is preferred when documented.