ICD-10 Code D84.821: Immunodeficiency due to drugs
D84.821 is a billable ICD-10 diagnosis code used to classify Immunodeficiency due to drugs in medical records and claims. You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records. ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89).
What is this code?
ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89).
When is it used?
- May be used when a clinician documents immunodeficiency due to drugs in a patient's medical record.
- May appear in hospital records, claims, referrals, and clinical documentation.
- This code can be used as a clinically usable diagnosis entry in standardized coding workflows.
What it does not mean
- A code alone does not explain severity, treatment plan, or outcome.
- A medical code should not be treated as a substitute for a doctor's diagnosis or advice.
Code hierarchy
Official coding notes
- Immunodeficiency due to (current or past) medication
- code for adverse effect if applicable, to identify adverse effect of drug (T36-T50 with fifth or six character 5)
- code, if applicable, for associated long term (current) drug therapy drug or medication such as:
- long term (current) drug therapy systemic steroids (Z79.52)
- other long term (current) drug therapy (Z79.899)
- code for adverse effect if applicable, to identify adverse effect of drug (T36-T50 with fifth or six character 5)
- code, if applicable, for associated long term (current) drug therapy drug or medication such as:
- long term (current) drug therapy systemic steroids (Z79.52)
- other long term (current) drug therapy (Z79.899)
Where you may see this code
You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.
Related specialists
Related codes
Coverage-related procedures and services
Coding guidelines
Common synonyms
Frequently asked questions
About this content
This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.