Alphabetic Index FY2027

Q21.1

Atrial septal defect

FY2027Chapter 17: Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders/Q20–Q28 Congenital malformations of the circulatory system

Non-billable headerNot valid on its own. Use one of the more specific codes under it.

Q21.1 is a non-billable ICD-10-CM code header for atrial septal defect. Report a more specific code from it instead. It is part of the FY2027 code set, effective October 1, 2026. The more specific codes under it are Q21.10 Atrial septal defect, unspecified; Q21.11 Secundum atrial septal defect; Q21.12 Patent foramen ovale; Q21.13 Coronary sinus atrial septal defect and 4 more. Its coding notes include 1 Excludes1 entry and 2 Excludes2 entries.

Guidelines tip

From the FY2027 Official Guidelines. ICD10Ref adds no rules of its own.

Chapter 17 codes can be used for life. Manifestations that are an inherent part of a specifically coded anomaly are not coded separately. A corrected malformation is reported with a personal history code.

Guidelines I.C.17Congenital malformations and genetic disordersRead the official text

Excludes1

Not coded here. The listed conditions generally should not be reported together.

Inherited from Q21 Congenital malformations of cardiac septa
  • acquired cardiac septal defect (I51.0)

Excludes2

Not included here. Both codes may be reported if the patient has both conditions.

This code
  • ostium primum atrial septal defect (type I) (Q21.20)
Also from chapter/block level (1 note)
Inherited from Chapter 17 Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders
  • inborn errors of metabolism (E70-E88)

Notes

Also from chapter/block level (1 note)
Inherited from Chapter 17 Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders
  • Codes from this chapter are not for use on maternal records

More specific codes under Q21.1 8