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Q21.1

Q21.1: Atrial septal defect

Non-billable headerICD-10-CM

Q21.1 is a non-billable header ICD-10-CM code for atrial septal defect. It cannot be billed on its own: choose one of the more specific child codes below.

Excludes2: not included here, but may coexist

The excluded condition is not part of this code, but a patient can have both. You may code both.

  • ostium primum atrial septal defect (type I) (Q21.20)

Excludes1 inherited from the categories above Q21.1

A category’s note binds every code beneath it.

Written on Q21: Congenital malformations of cardiac septa

  • acquired cardiac septal defect (I51.0)

Risk adjustment

No CMS-HCC V28 category: this code does not change a RAF score.

Code history

Unchanged in every release from FY2024 to FY2027.

Code to one of these instead Q21.1

8 child codes. Green means billable.

Other codes under Q21

ICD-10-CMFY2027· effective October 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release: see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.