Q21.1 ICD-10-CA code: Atrial septal defect
Q21.1 is the ICD-10-CA code for “Atrial septal defect” in CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026.
Official description
Q21.1Atrial septal defect
ICD-10-CA · Canada · Also written Q211
Index terms
Entries in CIHI’s alphabetical index that lead to Q21.1. Searching the index by the condition the note names is how coders reach this code.
- Common, atrium
- Patent, foramen, ovale
- Patent, ostium secundum
- Agenesis, septum, atrial
- Patent, foramen, botalli
- Nonclosure, foramen, ovale
- Nonclosure, foramen, botalli
- Patent, interauricular septum
- Cor, triloculare, biventriculare
- Defect, defective, sinus venosus
- Closure, foramen ovale, imperfect
- Defect, defective, coronary sinus
- Lutembacher's disease or syndrome
- Defect, defective, auricular septal
- Defect, defective, ostium, secundum
- Defect, defective, interatrial septal
- Defect, defective, interauricular septal
- Closure, interauricular septum, defective
- Imperfect, closure (congenital), foramen, ovale
- Imperfect, closure (congenital), septum, atrial
- Foramen ovale (nonclosure) (patent) (persistent)
- Imperfect, closure (congenital), foramen, botalli
- Abnormal, abnormality, abnormalities, sinus venosus
- Imperfect, closure (congenital), ostium, interatrial
- Imperfect, closure (congenital), septum, interatrial
- Persistence, persistent (congenital), foramen, ovale
- Persistence, persistent (congenital), foramen, botalli
- Persistence, persistent (congenital), ostium, secundum
- Imperfect, closure (congenital), ostium, interauricular
- Imperfect, closure (congenital), septum, interauricular
- Defect, defective, atrial septal (ostium secundum) (type II)
- Ostium, secundum (arteriosum) (defect) (patent) (persistent)
- Anomaly, anomalous (congenital) (unspecified type), atrial, septa
- Absence (organ or part) (complete or partial), atrial septum (congenital)
- Absence (organ or part) (complete or partial), septum, atrial (congenital)
- Anomaly, anomalous (congenital) (unspecified type), heart, septum, auricular
Notes for Q21.1
As CIHI prints them, with any note Q21.1 takes from the headings above it.
Includes
- Coronary sinus defectPatent or persistent:• foramen ovale• ostium secundum defect (type II)Sinus venosus defect
Excludes
Conditions classified elsewhere.
- Acquired cardiac septal defect (I51.0)From Q21 Congenital malformations of cardiac septa
- Inborn errors of metabolism (E70-E90)From Chapter 17: Congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
Where Q21.1 sits
- 1ChapterChapter 17: Congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
- 2Block Q20-Q28Congenital malformations of the circulatory system
- 3Category Q21Congenital malformations of cardiac septa
- 4Valid code Q21.1Atrial septal defect
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 Q21.1 mean?
Q21.1 is the ICD-10-CA code for “Atrial septal defect” in CIHI’s ICD-10-CA FY 2026–2027 release.
Where is Q21.1 in ICD-10-CA?
Q21.1 sits under Q21 Congenital malformations of cardiac septa, within Q20-Q28 Congenital malformations of the circulatory system, within Chapter 17: Congenital malformations, deformations and chromosomal abnormalities (Q00-Q99).
What coding notes apply to Q21.1?
ICD-10-CA lists Includes, Excludes notes for Q21.1, 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.