2026 ICD-10-CM Diagnosis Code Q20.5Discordant atrioventricular connection

ICD-10-CM Codes›Q00-Q99›Q20-Q28›Q20

ICD-10-CM Q20.5
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Q20.5 is a billable ICD-10-CM diagnosis code for discordant atrioventricular connection. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 306 through 307. The code is exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Cardiac and circulatory congenital anomalies.

Code Identity

ICD-10-CM Code
Q20.5
Billable Status
Yes — Valid for Submission
Code Describes
Discordant atrioventricular connection
Short Description
Discordant atrioventricular connection
Same as the full description in the CMS dataset.
Parent Code
Q20
Congenital malformations of cardiac chambers and connections

Code Classification

ChapterQ00-Q99Congenital malformations, deformations and chromosomal abnormalities
SectionQ20-Q28Congenital malformations of the circulatory system
CategoryQ20Congenital malformations of cardiac chambers and connections
This CodeQ20.5Discordant atrioventricular connection

Present on Admission (POA)Billing

Q20.5 is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Abnormal atrioventricular connection
  • Abnormal atrioventricular connection - biventricular
  • Abnormal atrioventricular connection - univentricular
  • Ambiguous atrioventricular connection
  • Congenital abnormality of tricuspid leaflet
  • Corrected transposition of great vessels
  • Discordant atrioventricular connection
  • Discordant ventriculoarterial connection
  • Double outlet ventriculoarterial connections
  • Doubly committed ventricular septal defect in double outlet ventriculoarterial connection
  • Ebstein's anomaly
  • Ebstein's anomaly of left sided tricuspid valve with discordant atrioventricular connections
  • L - transposition of the great vessels

Tabular List NotesGuidance

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

Inclusion Terms

  • Corrected transposition
  • Levotransposition
  • Ventricular inversion

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Communication
      • between
        • left ventricle and right atrium
    • Corrected transposition
    • Discordant connection
      • atrioventricular (congenital)
    • Inversion
      • ventricular
    • Levotransposition
    • Transposition(congenital)
      • corrected
    • Ventricle, ventricular
      • inversion

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR MAL001
Cardiac and circulatory congenital anomalies
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Discordant Ventriculoarterial Connection

    a rare congenital cardiovascular abnormality in which the aorta arises from the right ventricle and the pulmonary artery arises from the left ventricle.

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.

Convert Q20.5 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
745.12 Correct transpos grt ves
Approximate The match is approximate rather than exact.

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 Q20.5Overview

Is Q20.5 (Congenital malformations of cardiac chambers and connections) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report discordant atrioventricular connection on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does Q20.5 group to?

When discordant atrioventricular connection is the principal diagnosis on an inpatient stay, it groups to MS-DRG 306, 307, with relative weights from 0.9132 to 1.5758 depending on complications. Higher weights mean higher Medicare reimbursement.

Is Q20.5 exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for discordant atrioventricular connection on inpatient claims.

What is the ICD-9 equivalent of Q20.5?

Under the General Equivalence Mappings, discordant atrioventricular connection converts to ICD-9-CM 745.12 (correct transpos grt ves). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.