Q21.16: Sinus venosus atrial septal defect, unspecified
Q21.16 is the billable ICD-10-CM diagnosis code for Sinus venosus atrial septal defect, unspecified. It is a fully specified code, so it can be reported on a claim (subject to clinical documentation and your payer's rules).
Frequently asked questions
What is ICD-10-CM code Q21.16?
Q21.16 is the ICD-10-CM diagnosis code for Sinus venosus atrial septal defect, unspecified. It belongs to category Q21 (Congenital malformations of cardiac septa).
Is Q21.16 a billable code?
Yes. Q21.16 is a billable, fully specified ICD-10-CM code, so it can be used on a claim (subject to documentation and payer rules).
What category does Q21.16 belong to?
Q21.16 is part of ICD-10-CM category Q21 — Congenital malformations of cardiac septa, which has 34 billable codes.
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Informational only, not coding or medical advice. Verify against the official ICD-10-CM (FY2026) and your payer's guidelines.
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