Q21.20 – Atrioventricular septal defect, unspecified as to partial or complete
ICD-10-CM 2027 diagnosis code · Congenital malformations of the circulatory system
- Code
Q21.20(claims format:Q2120)- Description
- Atrioventricular septal defect, unspecified as to partial or complete
- Short description
- Atrioventricular septal defect, unsp as to part or complete
- Billable
- Yes – valid for HIPAA-covered transactions
- Valid for
- Dates of service October 1, 2026 – September 30, 2027 (FY2027)
- Chapter
- 17. Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders (Q00-QA1)
- Block
- Q20-Q28 Congenital malformations of the circulatory system
- Parent codes
- Q21 › Q21.2
Notes for Q21.20
- Atrioventricular canal, NOS
- Endocardial cushion defect NOS
- Ostium primum atrial septal defect (type I) NOS
Notes inherited from parent codes
Instructional notes at a category or block level apply to every code below it.
Q21 – Congenital malformations of cardiac septa
- acquired cardiac septal defect (I51.0)
Q21.2 – Atrioventricular septal defect
- Atrioventricular canal defect
- Endocardial cushion defect
- Ostium primum atrial septal defect (type I)
Index terms for Q21.20
Entries in the ICD-10-CM alphabetic index that lead to this code:
- Ostium, primum
- Single, atrium
- Canal, atrioventricular
- Defect, defective, ostium, primum
- Defect, defective, cushion, endocardial
- Persistence, persistent, ostium, primum
- Endocardium, endocardial, cushion defect
- Defect, defective, atrioventricular, canal
- Defect, defective, atrioventricular, septum
- Imperfect, closure, atrioventricular ostium
- Persistence, persistent, atrioventricular canal
- Defect, defective, atrial septal, ostium primum type
- Defect, defective, atrioventricular, septal, unspecified as to partial or complete
Related codes in Q21.2
Frequently asked questions
What is ICD-10 code Q21.20?
Q21.20 is the ICD-10-CM code for atrioventricular septal defect, unspecified as to partial or complete, in the block Q20-Q28 (Congenital malformations of the circulatory system).
Is Q21.20 a billable code?
Yes. Q21.20 is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.
What category does Q21.20 belong to?
It belongs to category Q21 – Congenital malformations of cardiac septa.
Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.