2026 ICD-10-CM Diagnosis Code Q24.6Congenital heart block

ICD-10-CM Codes›Q00-Q99›Q20-Q28›Q24

ICD-10-CM Q24.6
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Q24.6 is a billable ICD-10-CM diagnosis code for congenital heart block. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 308 through 310. The code is exempt from POA reporting. Coders also document this condition as complete atrioventricular block. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Cardiac and circulatory congenital anomalies.

Code Identity

ICD-10-CM Code
Q24.6
Billable Status
Yes — Valid for Submission
Code Describes
Congenital heart block
Short Description
Congenital heart block
Same as the full description in the CMS dataset.
Parent Code
Q24
Other congenital malformations of heart

Code Classification

ChapterQ00-Q99Congenital malformations, deformations and chromosomal abnormalities
SectionQ20-Q28Congenital malformations of the circulatory system
CategoryQ24Other congenital malformations of heart
This CodeQ24.6Congenital heart block

Present on Admission (POA)Billing

Q24.6 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.

  • Complete atrioventricular block
  • Congenital complete atrioventricular heart block
  • Congenital conduction defect
  • Congenital heart block
  • Congenital incomplete atrioventricular heart block
  • Partial atrioventricular block

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.

    • Block, blocked
      • atrioventricular (incomplete) (partial)
        • complete
          • congenital
    • Block, blocked
      • atrioventricular (incomplete) (partial)
        • congenital
    • Block, blocked
      • heart
        • congenital

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

Patient EducationClinical

Arrhythmia

An arrhythmia is a problem with the rate or rhythm of your heartbeat. Your heart beats too quickly, too slowly, or with an irregular pattern. Changes in the electrical signals that control your heartbeat cause arrhythmias.

The full article covers:

  • What is an arrhythmia?
  • What causes an arrhythmia?
  • What are the symptoms of an arrhythmia?
  • How is an arrhythmia diagnosed?
  • What are the treatments for an arrhythmia?
  • Can arrhythmias be prevented?

Read the full article at MedlinePlus

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

Convert Q24.6 to ICD-9-CMHistory

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

ICD-9-CM
746.86 Congenital heart block
Exact Match The mapping is direct, with no qualifiers.

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 Q24.6Overview

Is Q24.6 (Other congenital malformations of heart) a billable code?

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

What MS-DRG does Q24.6 group to?

When congenital heart block is the principal diagnosis on an inpatient stay, it groups to MS-DRG 308, 309, 310, with relative weights from 0.5661 to 1.2040 depending on complications. Higher weights mean higher Medicare reimbursement.

Is Q24.6 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 congenital heart block on inpatient claims.

What is the ICD-9 equivalent of Q24.6?

Under the General Equivalence Mappings, congenital heart block converts to ICD-9-CM 746.86 (congenital heart block). The mapping is a direct match.

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.