ICD-10 Code D81.39 – Other adenosine deaminase deficiency (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D81.39 – Other adenosine deaminase deficiency
What it is
Use this code for adenosine deaminase deficiency not described by a more specific ICD-10-CM option. It identifies a rare inherited immunodeficiency that impairs normal immune function.
Clinical signs
Clinical features vary; refer to documentation. Standard references describe recurrent or severe infections, lymphopenia, and findings consistent with combined immunodeficiency.
When to use this code
Assign D81.39 when the record documents adenosine deaminase deficiency and the provider does not specify a more exact subtype. Use it for confirmed congenital or inherited deficiency, not for general immune disorder workups. Check documentation if the diagnosis is only suspected.
Do not use for
Do not use this code for nonspecific immunodeficiency, enzyme deficiency without ADA involvement, or abnormal screening results alone. If the chart names a different primary immunodeficiency, code that condition instead.
Coding tip
Look for the provider’s exact wording; the “other” category is appropriate only when no more specific ADA deficiency code applies.