Q21.3 Tetralogy of Fallot
The ICD-10-CM code for Tetralogy of Fallot is Q21.3 (FY2026). It is a billable, claim-ready diagnosis code.
Classification
- Section
- Q20-Q28: Congenital malformations of the circulatory system (Q20-Q28)
- Category Q21
- 20 codes (17 billable)
- FY2026 Status
- Stable since FY2024
Also Known As
ICD-10-CM Alphabetic Index entries that lead to Q21.3:
- Tetralogy of Fallot
- Dextraposition, aorta › in tetralogy of Fallot
- Syndrome › Fallot's
- Fallot's › tetrad or tetralogy
- Anomaly, anomalous (congenital) (unspecified type) › heart › tetralogy of Fallot
- Defect, defective › ventricular septal › in tetralogy of Fallot
- Defect, defective › interventricular septal › in tetralogy of Fallot
- Defect, defective › interventricular septal › with dextroposition of aorta, pulmonary stenosis and hypertrophy of right ventricle
Inclusion Terms
- Ventricular septal defect with pulmonary stenosis or atresia, dextroposition of aorta and hypertrophy of right ventricle.
U.S. Hospital Utilization
- An estimated 7,755 U.S. inpatient stays in 2023 included Q21.3 among the documented diagnoses.
- 2,490 stays listed it as the principal diagnosis.
Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.
Official Coding Guidelines
POA indicator for congenital conditions/anomalies and Q00-Q99 exceptionCongenital conditions and anomalies Assign “Y” for congenital conditions and anomalies except for categories Q00- Q99, Congenital anomalies, which are on the exempt list. Congenital conditions are always considered present on admission.
Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026