D84.821 — Immunodeficiency due to drugs
D84.821 is a billable, specific ICD-10-CM code for immunodeficiency due to drugs. It is valid for submission on a claim.
Use additional code
Add a secondary code to capture the detail described below.
- 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)
Inclusion terms
Alternative wordings a physician may use in the chart for this same code.
- Immunodeficiency due to (current or past) medication
Risk adjustment
D84.821 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.
Medicare coverage
D84.821 is named in 14 Medicare coverage policies — 14 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A56464Billing and Coding: Flow Cytometry
- A56638Billing and Coding: Gastrointestinal Pathogen (GIP) Panels Utilizing Multiplex Nucleic Acid Amplification Techniques (NAATs)
- A56642Billing and Coding: Gastrointestinal Pathogen (GIP) Panels Utilizing Multiplex Nucleic Acid Amplification Techniques (NAATs)
- A57044Billing and Coding: Removal of Benign Skin Lesions
How D84.821 is indexed
Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to D84.821.
- Immunodeficiency›due to›drugs
- Immunodeficiency›due to›medication(current or past)
Related codes at this level
Codes that share D84.82. If D84.821 is not quite right, the correct code is usually one of these.
Questions about D84.821
- Is D84.821 a billable ICD-10-CM code?
- Yes. D84.821 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does D84.821 sit in the tabular list?
- Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89), in the block Certain disorders involving the immune mechanism (D80-D89).