Q21.1 Atrial septal defect

Not billable (header)Chapter 17

Report one of the more specific codes below.

Check coverage with this diagnosis

Codes under this one

Q21.10 Atrial septal defect, unspecified
Q21.11 Secundum atrial septal defect
Q21.12 Patent foramen ovale
Q21.13 Coronary sinus atrial septal defect
Q21.14 Superior sinus venosus atrial septal defect
Q21.15 Inferior sinus venosus atrial septal defect
Q21.16 Sinus venosus atrial septal defect, unspecified
Q21.19 Other specified atrial septal defect

Instructional notes

Chapter 17

Excludes2Not included here: the patient may have both; report both when both are present.

inborn errors of metabolism (E70-E88)

Notes

Codes from this chapter are not for use on maternal records

Q21

Excludes1Not coded here: never report with this code, except when the two conditions are unrelated.

acquired cardiac septal defect (I51.0)

This code

Excludes2Not included here: the patient may have both; report both when both are present.

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

Chapter 17: Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders (Q00-QA1) · Q20-Q28 Congenital malformations of the circulatory system (Q20-Q28)

Source: ICD-10-CM FY 2027 code descriptions and tabular list (CMS and CDC National Center for Health Statistics), effective 2026-10-01 through 2027-09-30 · CMS ICD-10 files. HCC mapping: CMS-HCC V28, payment year 2027. As of 2026-11-04.

Coverage and payment depend on the claim details; confirm with the Medicare Administrative Contractor.