ICD-10 Code D81.0 – Severe combined immunodeficiency [SCID] with reticular dysgenesis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D81.0 – Severe combined immunodeficiency [SCID] with reticular dysgenesis
What it is
D81.0 identifies severe combined immunodeficiency with reticular dysgenesis, a rare inherited immune disorder. It reflects profound defects in both cellular and humoral immunity, with abnormal development of immune cells and other marrow-derived cells.
Clinical signs
Clinical features vary; refer to documentation. Standard references describe severe, early-onset infections, failure to thrive, and marked lymphopenia, with reticular dysgenesis also associated with hearing loss and absent or severely reduced neutrophil production.
When to use this code
Use D81.0 when the record specifically documents SCID with reticular dysgenesis. It is appropriate for confirmed congenital immunodeficiency cases, especially when the provider names the reticular dysgenesis subtype. If the subtype is not stated, check documentation before assigning this code.
Do not use for
Do not use this code for other SCID variants, isolated neutropenia, or unspecified immunodeficiency. If the chart only says “combined immunodeficiency” or “immune deficiency” without reticular dysgenesis, check documentation.
Coding tip
Assign D81.0 only when the provider documents the reticular dysgenesis form of SCID; otherwise query for the exact diagnosis.