ICD-10 Code D84.821 – Immunodeficiency due to drugs (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D84.821 – Immunodeficiency due to drugs
What it is
D84.821 identifies acquired immune suppression caused by a medication. Use it when a drug, not a primary immune disorder, is documented as the reason the patient is immunodeficient.
Clinical signs
Clinical features vary; refer to documentation. You may see recurrent or unusual infections, poor immune response, or provider-noted drug-related immunosuppression.
When to use this code
Use this code when the record states immunodeficiency is due to a medication, such as an immunosuppressant or other drug effect. It supports the cause of the immune deficit, not the infection itself. If the note only says “immunocompromised” without a cause, check documentation.
Do not use for
Do not use it for congenital or primary immunodeficiency disorders, or for immunodeficiency caused by another condition. Do not assign it when the chart does not link the immune problem to a drug.
Coding tip
Look for explicit provider documentation connecting the immunodeficiency to a medication before assigning D84.821.