2026 ICD-10-CM Diagnosis Code Q20Congenital malformations of cardiac chambers and connections

ICD-10-CM Codes›Q00-Q99›Q20-Q28›Q20

ICD-10-CM Q20
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Q20 is a non-billable ICD-10-CM category code for congenital malformations of cardiac chambers and connections, so it cannot be submitted on claims. Use a more specific code from this category instead, such as Q20.0, Q20.1, Q20.2, and Q20.3.

Code Identity

ICD-10-CM Code
Q20
Billable Status
No — Non-Billable Category
Code Describes
Congenital malformations of cardiac chambers and connections
Chapter
Q20-Q28
Congenital malformations of the circulatory system

Code Classification

ChapterQ00-Q99Congenital malformations, deformations and chromosomal abnormalities
SectionQ20-Q28Congenital malformations of the circulatory system
CategoryQ20Congenital malformations of cardiac chambers and connections
This CodeQ20Congenital malformations of cardiac chambers and connections

Specific Coding for Congenital malformations of cardiac chambers and connectionsOverview

Non-specific codes like Q20 require more characters. Use one of these billable codes instead:

  • Use Q20.0 for Common arterial trunk

  • Use Q20.1 for Double outlet right ventricle

  • Use Q20.2 for Double outlet left ventricle

  • Use Q20.3 for Discordant ventriculoarterial connection

  • Use Q20.4 for Double inlet ventricle

  • Use Q20.5 for Discordant atrioventricular connection

  • Use Q20.6 for Isomerism of atrial appendages

  • Use Q20.8 for Other congenital malformations of cardiac chambers and connections

  • Use Q20.9 for Congenital malformation of cardiac chambers and connections, unspecified

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Type 1 Excludes

  • dextrocardia with situs inversus Q89.3
  • mirror-image atrial arrangement with situs inversus Q89.3

Patient EducationClinical

Congenital Heart Defects

Congenital heart defects (CHDs) are problems with the structure of the heart. "Congenital" means that that the problems are present at birth. These defects happen when a fetus's heart doesn't develop normally during pregnancy. Congenital heart defects are the most common type of birth defect.

The full article covers:

  • What are congenital heart defects?
  • What causes congenital heart defects?
  • Who is more likely to have a baby with a congenital heart defect?
  • What are the symptoms of congenital heart defects?
  • What other problems do congenital heart defects cause?
  • How are congenital heart defects diagnosed?
  • What are the treatments for congenital heart defects?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About Q20Overview

Is Q20 (Congenital malformations of cardiac chambers and connections) a billable code?

No. This is a category header that groups the codes for congenital malformations of cardiac chambers and connections, and headers cannot be submitted on claims. Claims for congenital malformations of cardiac chambers and connections need a more specific code from this category, such as Q20.0, Q20.1, and Q20.2.