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Q21.3

Q21.3Tetralogy of Fallot

Billable / specific codeICD-10-CMPOA exempt

Q21.3 is a billable, specific ICD-10-CM code for tetralogy of fallot. It is valid for submission on a claim.

Inclusion terms

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

  • Ventricular septal defect with pulmonary stenosis or atresia, dextroposition of aorta and hypertrophy of right ventricle.

Risk adjustment

Q21.3 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Medicare coverage

Q21.3 is named in 28 Medicare coverage policies 28 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A52458Automatic External Defibrillators - Policy Article
  • A52458Automatic External Defibrillators - Policy Article
  • A52850Billing and Coding: Cardiac Catheterization and Coronary Angiography
  • A52868Billing and Coding: Transesophageal Echocardiography (TEE)

How Q21.3 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to Q21.3.

  • Tetralogy of Fallot
  • Dextraposition, aortain tetralogy of Fallot
  • Fallot'stetrad or tetralogy
  • SyndromeFallot's
  • Anomaly, anomaloushearttetralogy of Fallot
  • Defect, defectiveinterventricular septalin tetralogy of Fallot
  • Defect, defectiveinterventricular septalwith dextroposition of aorta, pulmonary stenosis and hypertrophy of right ventricle
  • Defect, defectiveventricular septalin tetralogy of Fallot
  • Hypertrophy, hypertrophicventricle, ventricularin tetralogy of Fallot
  • Stenosis, stenoticpulmonaryin tetralogy of Fallot
  • Stenosis, stenoticpulmonarywith ventricular septal defect, transposition of aorta, and hypertrophy of right ventricle
  • Anomaly, anomalousheartseptuminterventricularwith pulmonary stenosis or atresia, dextraposition of aorta and hypertrophy of right ventricle

Related codes at this level

Codes that share Q21. If Q21.3 is not quite right, the correct code is usually one of these.

Questions about Q21.3

Is Q21.3 a billable ICD-10-CM code?
Yes. Q21.3 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does Q21.3 sit in the tabular list?
Congenital malformations, deformations and chromosomal abnormalities (Q00-QA0), in the block Congenital malformations of the circulatory system (Q20-Q28).
ICD-10-CMFY2026-Apr· effective April 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.