D84.1 ICD-10-CA code: Defects in the complement system
D84.1 is the ICD-10-CA code for “Defects in the complement system” in CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026.
Official description
D84.1Defects in the complement system
ICD-10-CA · Canada · Also written D841
Index terms
Entries in CIHI’s alphabetical index that lead to D84.1. Searching the index by the condition the note names is how coders reach this code.
- Giant, urticaria, hereditary
- Urticaria, giant, hereditary
- Urticaria, larynx, hereditary
- Bannister's disease, hereditary
- Defect, defective, complement system
- Edema, edematous, periodic, hereditary
- Quincke's disease or edema, hereditary
- Edema, edematous, Quincke's, hereditary
- Edema, edematous, essential, acute, hereditary
- Urticaria, with angioneurotic edema, hereditary
- Edema, edematous, circumscribed, acute, hereditary
- Deficiency, deficient, C1 esterase inhibitor (C1 INH)
- Angioedema (allergic) (any site) (with urticaria), hereditary
- Angioneurotic edema (allergic) (any site) (with urticaria), hereditary
- Edema, edematous, angioneurotic (allergic) (any site) (with urticaria), hereditary
- Edema, edematous, glottis, glottic, glottidis (obstructive) (passive), allergic, hereditary
Notes for D84.1
As CIHI prints them, with any note D84.1 takes from the headings above it.
Includes
- C1 esterase inhibitor [C1-INH] deficiency
- Defects in the complement systemimmunodeficiency disorders, except human immunodeficiency virus [HIV] diseasesarcoidosisFrom D80-D89 Certain disorders involving the immune mechanism
Excludes
Conditions classified elsewhere.
- 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 D84.1 sits
- 1ChapterChapter 3: Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89)
- 2Block D80-D89Certain disorders involving the immune mechanism
- 3Category D84Other immunodeficiencies
- 4Valid code D84.1Defects in the complement system
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.
Frequently asked questions
What does ICD-10-CA code D84.1 mean?
D84.1 is the ICD-10-CA code for “Defects in the complement system” in CIHI’s ICD-10-CA FY 2026–2027 release.
Where is D84.1 in ICD-10-CA?
D84.1 sits under D84 Other 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 D84.1?
ICD-10-CA lists Includes, Excludes notes for D84.1, 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.