Z423 – Electrophysiologic pacing, mapping and ablation with advanced mapping system or procedure duration >4 hours
OHIP Psychiatric Code — DIAGNOSTIC AND THERAPEUTIC PROCEDURES · Schedule of Benefits
Electrophysiologic Pacing, Mapping and Ablation with the use of an advanced nonfluoroscopic computerized mapping and navigation system ("advanced mapping system") and/or procedure duration >4 hours. This procedure includes percutaneous access, insertion of catheters and electrodes, electrocardiograms, intracardiac echocardiograms and image guidance when rendered. It is only eligible for payment when rendered with G176 or G177. Commentary: As of October 2009, the advanced mapping system is typically used in hospital for the mapping of various atrial and ventricular arrhythmias, and congenital heart disease arrhythmia. Examples of procedures lasting more than 4 hours and not utilizing the advanced mapping system are mapping and ablation of multiple accessory pathways and/or thick band accessory pathway(s).
When to Use
- Use Z423 when performing complex electrophysiologic procedures that utilize advanced nonfluoroscopic computerized mapping and navigation systems, such as CARTO or EnSite, in conjunction with G176 or G177.
- Use Z423 for lengthy electrophysiologic procedures exceeding 4 hours of total duration, even if an advanced mapping system is not utilized, provided it is billed with G176 or G177.
Common Pitfalls
- Billing Z423 as a standalone code; it is strictly an add-on and will be rejected if not submitted on the same claim as G176 or G177.
- Failing to document the specific advanced mapping system used or the total procedure duration in the operative report, which is required to justify the Z423 claim during an audit.
Billing Tips
- Ensure the start and end times of the procedure are clearly recorded in the patient's chart to substantiate the >4 hour duration requirement if the claim is audited.
Effective: April 1, 2025
J. Diagnostic and Therapeutic Procedures
DIAGNOSTIC AND THERAPEUTIC PROCEDURES
Surgical
Digestive System Surgical Procedures
All insured services must be documented in appropriate records to establish that: 1. an insured service was provided; 2. the service for which the account is submitted is the service that was rendered; and 3. the service was medically necessary.
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