| Billable | No — use a more specific child code |
| Chapter | Chapter 17: Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders (Q00-QA1) |
| Section | Congenital malformations of the circulatory system (Q20-Q28) |
| Parent code | Q23 — Congenital malformations of aortic and mitral valves |