ICD-10-CM 2027 diagnosis code
D81Combined immunodeficiencies
D81 is a header code, so it can't be reported by itself. Choose one of the 10 more specific codes beneath it.
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About D81
D81 is the ICD-10-CM diagnosis code for combined immunodeficiencies. It belongs to block D80-D89 (certain disorders involving the immune mechanism) and chapter 3 (diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism). It is a header code, so it can't be reported by itself; one of its 10 subcodes must be used instead.
To report this condition, pick the subcode that matches the documentation: D81.0 (dysgenesis), D81.1 (numbers), D81.2 (numbers), D81.3 (deficiency), D81.4 (syndrome), D81.5 (deficiency), D81.6 (deficiency), D81.7 (deficiency) and 2 more.
Don't report D81 together with the conditions in its Excludes1 note: autosomal recessive agammaglobulinemia (Swiss type) (D80.0).
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
Specific codes under D81
- D81.0Severe combined immunodeficiency [SCID] with reticular dysgenesisBillable
- D81.1Severe combined immunodeficiency [SCID] with low T- and B-cell numbersBillable
- D81.2Severe combined immunodeficiency [SCID] with low or normal B-cell numbersBillable
- D81.3Adenosine deaminase [ADA] deficiency
- D81.4Nezelof's syndromeBillable
- D81.5Purine nucleoside phosphorylase [PNP] deficiencyBillable
- D81.6Major histocompatibility complex class I deficiencyBillable
- D81.7Major histocompatibility complex class II deficiencyBillable
- D81.8Other combined immunodeficiencies
- D81.9Combined immunodeficiency, unspecifiedBillable
Coding notes
- autosomal recessive agammaglobulinemia (Swiss type) (D80.0)
Notes that apply from higher levels
Instructions written at a parent level also apply to D81.
Broader instructions also apply from D80-D89 Certain disorders involving the immune mechanism and Chapter 3: Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism.
Codes whose notes reference D81
- E79Excludes1
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about D81
Is D81 billable?
- No. D81 is a header code. Report one of its more specific subcodes instead.