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D81.9 ICD-10-CA code: Combined immunodeficiency, unspecified

D81.9 is the ICD-10-CA code for “Combined immunodeficiency, unspecified” in CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026.

Official description

D81.9

Combined immunodeficiency, unspecified

Short description: Combined immunodeficiency unspecified

ICD-10-CA · Canada · Also written D819

Index terms

Entries in CIHI’s alphabetical index that lead to D81.9. Searching the index by the condition the note names is how coders reach this code.

  • Immunodeficiency, combined
  • Agammaglobulinemia, lymphopenic
  • Syndrome, immunodeficiency, combined
  • Agammaglobulinemia, with, lymphopenia
  • Deficiency, deficient, immunity, combined
  • Immunodeficiency, combined, severe (SCID)

Notes for D81.9

As CIHI prints them, with any note D81.9 takes from the headings above it.

Includes

Excludes

Conditions classified elsewhere.

  • Autosomal recessive agammaglobulinaemia (Swiss type) (D80.0)From D81 Combined immunodeficiencies
  • Autoimmune disease (systemic) NOS (M35.9)functional disorders of polymorphonuclear neutrophils (D71)human immunodeficiency virus [HIV] disease (B24)human immunodeficiency virus [HIV] disease complicating pregnancy, childbirth and the puerperium (O98.7-)From D80-D89 Certain disorders involving the immune mechanism
  • Autoimmune disease (systemic) NOS (M35.9)certain conditions originating in the perinatal period (P00-P96)complications of pregnancy, childbirth and the puerperium (O00-O99)congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)endocrine, nutritional and metabolic diseases (E00-E90)human immunodeficiency virus [HIV] disease (B24)injury, poisoning and certain other consequences of external causes (S00-T98)neoplasms (C00-D48)symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)From Chapter 3: Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89)

Where D81.9 sits

  1. 1ChapterChapter 3: Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89)
  2. 2Block D80-D89Certain disorders involving the immune mechanism
  3. 3Category D81Combined immunodeficiencies
  4. 4Valid code D81.9Combined immunodeficiency, unspecified

Source and release

Data release
ICD-10-CA · FY 2026–2027
Effective date
Apr 1, 2026
Publisher
CIHI

This page is built from the ICD-10-CA catalog that Vero Codes reads when it suggests codes: Canadian Institute for Health Information’s FY 2026–2027 release, imported from the publisher’s file and checked against it. The description, notes and structured data come from the same record.

See D81.9 in the CIHI source

Frequently asked questions

What does ICD-10-CA code D81.9 mean?

D81.9 is the ICD-10-CA code for “Combined immunodeficiency, unspecified” in CIHI’s ICD-10-CA FY 2026–2027 release.

Where is D81.9 in ICD-10-CA?

D81.9 sits under D81 Combined immunodeficiencies, within D80-D89 Certain disorders involving the immune mechanism, within Chapter 3: Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89).

What coding notes apply to D81.9?

ICD-10-CA lists Includes, Excludes notes for D81.9, including those from the headings it sits under. They are listed on this page with where each one comes from.

Which ICD-10-CA release does this page use?

It uses CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026 to Mar 31, 2027. It is a reference: confirm the code against the current list and the payer’s rules before you submit it.

Codes beside D81.9

D81.0Severe combined immunodeficiency [SCID] with reticular dysgenesisD81.1Severe combined immunodeficiency [SCID] with low T- and B-cell numbersD81.2Severe combined immunodeficiency [SCID] with low or normal B-cell numbersD81.3Adenosine deaminase [ADA] deficiencyD81.4Nezelof's syndromeD81.5Purine nucleoside phosphorylase [PNP] deficiencyD81.6Major histocompatibility complex class I deficiencyD81.7Major histocompatibility complex class II deficiencyD81.8Other combined immunodeficiencies