D81 Combined immunodeficiencies

Category / Non-billable header 20 subcodes

Block: Certain disorders involving the immune mechanism (D80-D89)

Excludes 1 (cannot be coded together)

  • autosomal recessive agammaglobulinemia (Swiss type) (D80.0)

Subcodes

Each subcode links to a detail page with full clinical annotations.

Code Description Billable
D81..0 Severe combined immunodeficiency [SCID] with reticular dysgenesis Yes
D81..1 Severe combined immunodeficiency [SCID] with low T- and B-cell numbers Yes
D81..2 Severe combined immunodeficiency [SCID] with low or normal B-cell numbers Yes
D81..3 Adenosine deaminase [ADA] deficiency No
D81..30 Adenosine deaminase deficiency, unspecified Yes
D81..31 Severe combined immunodeficiency due to adenosine deaminase deficiency Yes
D81..32 Adenosine deaminase 2 deficiency Yes
D81..39 Other adenosine deaminase deficiency Yes
D81..4 Nezelof's syndrome Yes
D81..5 Purine nucleoside phosphorylase [PNP] deficiency Yes
D81..6 Major histocompatibility complex class I deficiency Yes
D81..7 Major histocompatibility complex class II deficiency Yes
D81..8 Other combined immunodeficiencies No
D81..81 Biotin-dependent carboxylase deficiency No
D81..810 Biotinidase deficiency Yes
D81..818 Other biotin-dependent carboxylase deficiency Yes
D81..819 Biotin-dependent carboxylase deficiency, unspecified Yes
D81..82 Activated Phosphoinositide 3-kinase Delta Syndrome [APDS] Yes
D81..89 Other combined immunodeficiencies Yes
D81..9 Combined immunodeficiency, unspecified Yes

Last reviewed: September 2026