Is ICD-10-CM code Q21 billable?

No, Q21 (Congenital malformations of cardiac septa) is a non-billable ICD-10-CM code. It must be coded to a more specific subcategory before it can be used for reimbursement.

What chapter does ICD-10-CM code Q21 belong to?

Q21 belongs to Chapter 17 of the ICD-10-CM tabular list: Q00–Q99 (Congenital Malformations, Deformations and Chromosomal Abnormalities).

Q21Non-billable

Congenital malformations of cardiac septa

Congenital Malformations, Deformations and Chromosomal Abnormalities·Congenital malformations of the circulatory system (Q20-Q28)·category·FY 2026

Use a more specific code (5 billable, 2 non-billable)

Q21.0Ventricular septal defect Q21.1Atrial septal defecthas subcodes Q21.2Atrioventricular septal defecthas subcodes Q21.3Tetralogy of Fallot Q21.4Aortopulmonary septal defect Q21.8Other congenital malformations of cardiac septa Q21.9Congenital malformation of cardiac septum, unspecified

CH17 Parent Instructions

Excludes2(Not included here. Code separately if applicable.)

inborn errors of metabolism (E70-E88)

Instructional Notes

Excludes1(Not coded here. Use a different code.)

acquired cardiac septal defect (I51.0)

Clinical Hierarchy

BillableHas subcodes

CH17Congenital malformations, deformations and chromosomal abnormalities (Q00-QA0)

Q20-Q28Congenital malformations of the circulatory system (Q20-Q28)

Q21Congenital malformations of cardiac septaNot billable

Q21.0Ventricular septal defectBillable

Q21.1Atrial septal defectSubcodes

Q21.2Atrioventricular septal defectSubcodes

Q21.3Tetralogy of FallotBillable

Q21.4Aortopulmonary septal defectBillable

Q21.8Other congenital malformations of cardiac septaBillable

Q21.9Congenital malformation of cardiac septum, unspecifiedBillable

MS-DRG Classification

2026

No direct MS-DRG triggers identified.