D81Header code — not billable
Combined immunodeficiencies
- Chapter
- 3. Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism
- Category
- D81
- Effective date
- October 1, 2026
Related codes in category D81
D81.0Severe combined immunodeficiency with reticular dysgenesisYesD81.1Severe combined immunodeficiency w low T- and B-cell numbersYesD81.2Severe combined immunodef w low or normal B-cell numbersYesD81.3Adenosine deaminase [ADA] deficiencyD81.30Adenosine deaminase deficiency, unspecifiedYesD81.31Severe combined immunodef due to adenosine deaminase deficYesD81.32Adenosine deaminase 2 deficiencyYesD81.39Other adenosine deaminase deficiencyYesD81.4Nezelof's syndromeYesD81.5Purine nucleoside phosphorylase [PNP] deficiencyYesD81.6Major histocompatibility complex class I deficiencyYesD81.7Major histocompatibility complex class II deficiencyYes
Frequently asked questions
What is ICD-10 code D81?
D81 is an ICD-10-CM diagnosis code for Combined immunodeficiencies.
Is D81 a billable code?
No. D81 is a category/header code, not billable on its own — use one of its more specific child codes instead.
What ICD-10-CM chapter is D81 in?
D81 falls under Chapter 3: Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism.
When did D81 become effective?
D81 has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.
What other codes are related to D81?
D81 belongs to category D81, which includes 12 other codes — see the related codes list on this page.
ICD-10-CM data maintained by CDC/CMS (public domain). Always verify codes with authoritative sources before making coding or billing decisions.