ICD-10 Code D84.822 – Immunodeficiency due to external causes (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D84.822 – Immunodeficiency due to external causes
What it is
D84.822 identifies immune deficiency caused by an external factor rather than an inherited disorder. Use it when documentation links the weakened immune state to an outside cause such as treatment, exposure, or another noninternal factor.
Clinical signs
Clinical features vary; refer to documentation. Commonly, records describe recurrent or unusual infections, poor immune response, or a clinician’s statement that immunity is reduced because of an external cause.
When to use this code
Use this code when the provider documents immunodeficiency as due to an external cause and not as a primary immune disorder. It may appear in problem lists, encounter diagnoses, or assessments tied to an outside exposure or intervention. If the cause is not clearly stated, check documentation.
Do not use for
Do not use this code for congenital or hereditary immunodeficiency disorders. Also avoid it when the chart only mentions infection risk, immunosuppression, or another condition without confirming immunodeficiency due to an external cause.
Coding tip
Code the external cause only when the record explicitly connects it to the immunodeficiency; otherwise, query or check documentation.