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Don’t miss these potential add-on codes.

As a medical coder working in cardiology, electrophysiology (EP), or interventional services, understanding how to appropriately code and submit claims for atrial fibrillation (AFib) ablation procedures is essential.

These procedures are high cost, often scrutinized by payers, and require precise coding, documentation, prior authorization, and claim submission to avoid delays or denials. This article walks you step-by-step through what you need to do to submit clean, compliant claims.

Understand Atrial Fibrillation and Medical Necessity Before Coding

Before coding an AFib ablation, you must confirm the clinical indication for the procedure in the medical record.

AFib means the patient has an arrhythmia characterized by chaotic electrical activity in the atria. It increases stroke risk and may lead to symptoms such as palpitations, fatigue, or dyspnea. The physician’s documentation should include clinical findings (for example, electrocardiogram [ECG], Holter monitor) and failed conservative treatments before ablation is considered.

Warning: Payers require evidence that the ablation is medically necessary based on documented arrhythmia and appropriate clinical criteria (for example, recurrent symptomatic AFib despite antiarrhythmic therapy). Unsupported or vague diagnoses are a top cause of claim denials.

Get Specific to Select the Correct ICD-10-CM Codes

Your claim’s ICD-10-CM diagnosis codes must clearly justify the ablation and be based on the medical documentation.

In other words, report the most specific AFib code that matches the clinical documentation. Some examples include:

• I48.0 (Paroxysmal atrial fibrillation)
• I48.1- (Persistent atrial fibrillation) with a 5^th character specifying whether this is permanent or “other” persistent AFib
• I48.2- (Chronic atrial fibrillation) with a 5^th character specifying whether this is permanent or “other” chronic AFib
• I48.91 (Unspecified atrial fibrillation), but only when documentation truly lacks specificity

Specific codes such as I48.0 or I48.19 help demonstrate medical necessity for potentially costly procedures like ablation. Do not use general symptom codes (for example, “palpitations”) or unrelated conditions that won’t support AFib ablation; this will increase the claim’s denial risk.

Understand Types of Atrial Fibrillation for ICD-10-CM Coding

For accurate ICD-10-CM reporting, it is important for you to understand how AFib is clinically classified, because each type maps to a different diagnosis code and affects medical necessity:

• Paroxysmal AFib is intermittent. Episodes start suddenly and stop on their own, typically lasting less than seven days (often less than 48 hours). Even though the rhythm returns to normal without intervention, paroxysmal AFib is a chronic condition and should be coded as such when documented. Report this type of AFib with I48.0.

• Persistent AFib lasts longer than seven days and does not self-terminate. Medical intervention such as cardioversion or medication is required to restore normal sinus rhythm. Providers may also document this as “long-standing persistent” when the arrhythmia has been continuous for more than 12 months. Code persistent AFib with I48.1 or I48.19, depending on the level of specificity documented.

• Chronic (permanent) AFib is continuous and accepted by the provider and patient as ongoing, with no further attempts planned to restore normal sinus rhythm. Management focuses on rate control and stroke prevention rather than rhythm conversion. Report this form of AFib with I48.2.

When reviewing documentation, always code the most specific type of AFib stated by the provider. Avoid defaulting to unspecified AFib codes unless the record truly lacks detail, as specificity supports medical necessity and reduces claim denials.

How to Report the Ablation Procedure for AFib

Correct CPT^® coding is critical for AFib claims. The CPT^® codes for ablation procedures reflect the type of electrophysiologic study and ablation the physician performs.

For AFib ablation procedures, you should focus primarily on 93656 (Comprehensive electrophysiologic evaluation with transseptal catheterizations, insertion and repositioning of multiple electrode catheters, induction or attempted induction of an arrhythmia including left or right atrial pacing/recording, and intracardiac catheter ablation of atrial fibrillation by pulmonary vein isolation, including intracardiac electrophysiologic 3-dimensional mapping, intracardiac echocardiography with imaging supervision and interpretation, right ventricular pacing/recording, and His bundle recording, when performed). This is the main code for pulmonary vein isolation (PVI) procedures typically used in AFib ablation cases.

Red flag: Do not report multiple primary EP ablation codes for one procedure. For example, do not report 93653 (Comprehensive electrophysiologic evaluation with insertion and repositioning of multiple electrode catheters, induction or attempted induction of an arrhythmia with right atrial pacing and recording and catheter ablation of arrhythmogenic focus, including intracardiac electrophysiologic 3-dimensional mapping, right ventricular pacing and recording, left atrial pacing and recording from coronary sinus or left atrium, and His bundle recording, when performed; 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) for a catheter ablation to treat supraventricular tachycardia as well as 93656 on the same date, unless separate medically necessary events occurred. Unbundled billing often triggers automated denials.

Remember These Add-On Codes

You can report add-on procedures when the physician performs more ablation beyond the primary site:

• +93655 (Intracardiac catheter ablation of a discrete mechanism of arrhythmia which is distinct from the primary ablated mechanism, including repeat diagnostic maneuvers, to treat a spontaneous or induced arrhythmia (List separately in addition to code for primary procedure))
• +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))

You must support add-on codes with clear documentation explaining why extra ablation was performed.

Check back next month for even more information on coding AFib ablations.

Suzanne Burmeister, BA, MPhil, Medical Writer and Editor