Q21.11

Billable

ChapterQ00–Q99

Ranksubcategory

Official Description

Secundum atrial septal defect

Metadata & Insights

•2026 ICD-10-CM Edition - Effective October 1, 2025.
•Billable/specific code (valid for reimbursement).
•Chapter 17: Congenital Malformations, Deformations and Chromosomal Abnormalities (Q00-Q99).

Instructional Notes

Includes

Fenestrated atrial septum
Patent or persistent ostium secundum defect (type II)

General instructions are available for the parent sections:

View CH17 Notes View Q21 Notes View Q21.1 Notes

Clinical Hierarchy

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

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

Q21Congenital malformations of cardiac septa

Q21.1Atrial septal defect

Q21.11Secundum atrial septal defect

Applicable Ancestor Context

The following parent sections contain instructions or notes that apply to Q21.11:

subcategoryQ21.1

Atrial septal defect

View context instructions

categoryQ21

Congenital malformations of cardiac septa

View context instructions

chapterCH17

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

View context instructions

Alphabetic Index Mentions

These are Diagnosis Index lookup paths that route to Q21.11. Use them as entry terms for search, then confirm final coding instructions in the Tabular List and notes above.

7 raw paths

Defect, defective2 unique routes

atrial septal

ostium secundum type (patent persistent) (type II)→Q21.11

ostium

secundum→Q21.11

Fenestration, fenestrated1 unique routes

atrial septum→Q21.11

Imperfect1 unique routes

closure (congenital)

atrium (secundum)→Q21.11

Ostium1 unique routes