Question: Can you please tell me which CPT® code should be used to bill for an AV node modification for atrial fibrillation without creation of a complete heart block? CPT® code 93650 seems to be the best choice to me. Ohio Subscriber Answer: Technically, add-on CPT® code +93657 (Additional linear or focal intracardiac catheter ablation of the left or right atrium for treatment of atrial fibrillation remaining after completion of pulmonary vein isolation (List separately in addition to code for primary procedure) is being provided, according to Christina Neighbors, MA, CPC, CCC, Coding Quality Auditor for Conifer Health Solutions, Coding Quality & Education Department, and member of AAPC's Certified Cardiology Coder steering committee. "However, the primary procedure this add-on procedure is attached to was not provided. In my opinion, CPT® code 93799 (Unlisted cardiovascular service or procedure) is the most appropriate code to capture," Neighbors adds. "If AVN block occurs inadvertently during the AV node modification and a permanent pacemaker is or will be implanted, then I would code 93650 (Intracardiac catheter ablation of atrioventricular node function, atrioventricular conduction for creation of complete heart block, with or without temporary pacemaker placement)." Reminder: Electrophysiology (EP) ablation codes are not always coded the same. These are always coded on a case-by-case basis and dependent on the intention. What's performed and the outcome will determine the appropriate procedure coding, Neighbors reiterates. Bonus: If AV node modification is performed for AVNRT (AV Node Re-entry Tachycardia), the appropriate CPT® code is 93653 (Comprehensive electrophysiologic evaluation including insertion and repositioning of multiple electrode catheters with induction or attempted induction of an arrhythmia with right atrial pacing and recording, right ventricular pacing and recording (when necessary), and His bundle recording (when necessary) with intracardiac catheter ablation of arrhythmogenic focus; with treatment of supraventricular tachycardia by ablation of fast or slow atrioventricular pathway, accessory atrioventricular connection, cavo-tricuspid isthmus or other single atrial focus or source of atrial re-entry).