D84.9 — Immunodeficiency, unspecified
D84.9 is a billable, specific ICD-10-CM code for immunodeficiency, unspecified. It is valid for submission on a claim.
Inclusion terms
Alternative wordings a physician may use in the chart for this same code.
- Immunocompromised NOS
- Immunodeficient NOS
- Immunosuppressed NOS
Other codes that can never be billed with D84.9
These codes carry an Excludes1 note pointing at D84.9. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading D84.9 alone.
- D84.81Immunodeficiency due to conditions classified elsewhere
Risk adjustment
D84.9 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
D84.9 is named in 15 Medicare coverage policies — 15 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A55717Billing and Coding: Lab: Flow Cytometry
- A56718Billing and Coding: Intravenous Immunoglobulin (IVIG)
- A57689Billing and Coding: Lab: Flow Cytometry
- A58710Billing and Coding: MolDX: Molecular Syndromic Panels for Infectious Disease Pathogen Identification Testing
How D84.9 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 D84.9.
- Immunocompromised NOS
- Immunodeficiency
- Immunodeficient NOS
- Immunosuppressed NOS
- Deficiency, deficient›immunity
Related codes at this level
Codes that share D84. If D84.9 is not quite right, the correct code is usually one of these.
Questions about D84.9
- Is D84.9 a billable ICD-10-CM code?
- Yes. D84.9 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does D84.9 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).