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Q21.16

Q21.16: Sinus venosus atrial septal defect, unspecified

Billable / specific codeICD-10-CMPOA exempt

Q21.16 is a billable, specific ICD-10-CM code for sinus venosus atrial septal defect, unspecified. It is valid for submission on a claim.

Check Q21.16 with the rest of the claim: free scrubber

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

  • Sinus venosus defect, NOS

Excludes1 inherited from the categories above Q21.16

A category’s note binds every code beneath it.

Written on Q21: Congenital malformations of cardiac septa

  • acquired cardiac septal defect (I51.0)

Excludes2 inherited from the categories above Q21.16

Not part of this code, but both may be coded when both are present.

Written on Q21.1: Atrial septal defect

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

Risk adjustment

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

Medicare coverage

Q21.16 is named in 14 Medicare coverage policies: 14 listing it as supporting medical necessity. Which one applies depends on your Medicare contractor.

  • A52850Billing and Coding: Cardiac Catheterization and Coronary Angiography
  • A52868Billing and Coding: Transesophageal Echocardiography (TEE)
  • A54111Billing and Coding: Speech Language Pathology (SLP) Services: Communication Disorders
  • A56500Billing and Coding: Cardiac Catheterization and Coronary Angiography

Alphabetic index entries that lead here

  • Abnormal, abnormality, abnormalities›sinus venosus
  • Defect, defective›sinus venosus
  • Defect, defective›atrial septal›sinus venosus

Code history

Unchanged in every release from FY2024 to FY2027.

Other codes under Q21.1

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.