TL;DR: The Centers for Medicare & Medicaid Services modified NCD 99 governing intraoperative ventricular mapping, with an effective date of March 7, 2026. Here's what billing teams need to know about coverage criteria and claim documentation before submitting.
CMS intraoperative ventricular mapping coverage policy under NCD 99 in the Medicare system covers a narrow set of cardiac conditions — and only those conditions. This policy has been modified as of 2026-03-07. The policy does not list specific CPT or HCPCS codes, which creates a real documentation challenge for intraoperative ventricular mapping billing. Your team needs to know exactly which clinical indications qualify before the next claim goes out.
Quick-Reference Table
| Field | Detail |
|---|---|
| Payer | CMS (Centers for Medicare & Medicaid Services) |
| Policy | Intraoperative Ventricular Mapping |
| Policy Code | NCD 99 |
| Change Type | Modified |
| Effective Date | 2026-03-07 |
| Impact Level | Medium |
| Specialties Affected | Cardiac Surgery, Electrophysiology, Cardiothoracic Surgery, Congenital Heart Surgery |
| Key Action | Audit all intraoperative ventricular mapping claims for documentation that maps directly to one of the four covered indications before submitting. |
CMS Intraoperative Ventricular Mapping Coverage Criteria and Medical Necessity Requirements 2026
The CMS intraoperative ventricular mapping coverage policy is restrictive by design. Medicare covers this procedure only for four specific clinical indications. If your documentation doesn't tie directly to one of those four, expect a claim denial.
Here's what the policy actually says. Intraoperative ventricular mapping is covered when used to:
| # | Covered Indication |
|---|---|
| 1 | Localize accessory pathways associated with Wolff-Parkinson-White (WPW) syndrome and other preexcitation syndromes |
| 2 | Map the sequence of atrial and ventricular activation for drug-resistant supraventricular tachycardias |
| 3 | Delineate the anatomical course of the His bundle and/or bundle branches during corrective cardiac surgery for congenital heart diseases |
| 4 | Direct surgical treatment of patients with refractory ventricular tachyarrhythmias |
Each of these is a hard boundary. CMS is not leaving room for clinical discretion outside these four uses. Medical necessity documentation must speak directly to one of these indications — not to intraoperative mapping in general.
The procedure itself involves recording cardiac electrical activity directly from the heart using a probe with electrodes. Sites include epicardial, intramural, and endocardial surfaces. The resulting map shows the sequence of electrical activation and helps the surgeon pinpoint exactly where to intervene. That clinical detail belongs in your operative documentation and should support your diagnosis codes.
NCD 99 in the Medicare system is a national coverage determination, which means it applies uniformly across all Medicare Administrative Contractors. This is not a local coverage determination that varies by region. Every MAC uses the same four-indication framework. That's actually helpful for billing teams — there's no regional variance to track.
This coverage policy does not mention prior authorization as a separate requirement. But that doesn't mean your MAC won't apply one administratively. Check with your MAC before assuming prior auth is off the table for high-cost cardiac surgery cases. If you're not sure how your MAC handles this, call them directly — don't assume the NCD silence means prior authorization is never required.
Reimbursement for intraoperative ventricular mapping runs through Inpatient Hospital Services and Physicians' Services benefit categories. Both paths are covered under NCD 99. Make sure your facility and professional claims are aligned on documentation — a mismatch between the operative note and the physician's billing can trigger a denial on either claim.
Coverage Indications at a Glance
| Indication | Status | Relevant Codes | Notes |
|---|---|---|---|
| Localize accessory pathways — Wolff-Parkinson-White (WPW) and other preexcitation syndromes | Covered | No specific CPT/HCPCS listed in NCD 99 | Diagnosis documentation must support WPW or named preexcitation syndrome |
| Map atrial and ventricular activation sequence — drug-resistant supraventricular tachycardias | Covered | No specific CPT/HCPCS listed in NCD 99 | Must document drug resistance; prior failed medical management should appear in the record |
| Delineate His bundle and/or bundle branch course — corrective surgery for congenital heart disease | Covered | No specific CPT/HCPCS listed in NCD 99 | Congenital heart disease diagnosis required; mapping must be part of a corrective surgical procedure |
| Direct surgical treatment — refractory ventricular tachyarrhythmias | Covered | No specific CPT/HCPCS listed in NCD 99 | Must document refractory status; prior treatment attempts should be in the clinical record |
| Any other intraoperative ventricular mapping use not listed above | Not Covered | — | Off-label use is not supported under NCD 99 |
CMS Intraoperative Ventricular Mapping Billing Guidelines and Action Items 2026
The absence of specific CPT or HCPCS codes in NCD 99 is the central billing challenge here. CMS sets the clinical boundaries but doesn't hand you the code list. Your billing team has to do that work. Here's how to approach it.
| # | Action Item |
|---|---|
| 1 | Identify the codes your physicians are currently billing for intraoperative ventricular mapping — do this before March 7, 2026. Since NCD 99 doesn't specify codes, your team is likely using procedure codes based on operative context. Pull claims from the last 12 months and confirm each one links to a covered indication. If a claim doesn't tie to WPW, drug-resistant supraventricular tachycardia, congenital heart surgery, or refractory ventricular tachyarrhythmias, flag it for review. |
| 2 | Update your operative documentation templates to explicitly call out the covered indication. The surgeon's note needs to name the condition — not just describe the mapping technique. "Mapping performed to localize accessory pathway in patient with confirmed Wolff-Parkinson-White syndrome" is what medical necessity looks like in this policy. Vague references to intraoperative mapping won't hold up in an audit. |
| 3 | Confirm drug resistance or refractory status is documented before billing the supraventricular tachycardia or ventricular tachyarrhythmia indications. Both of those indications require prior failed treatment. If the chart doesn't show it, the claim is exposed. A note that says "antiarrhythmic therapy failed" is not enough — the specific drugs tried, the duration, and the patient's response should all be in the record. |
| 4 | Contact your MAC to ask whether they apply prior authorization requirements for intraoperative ventricular mapping cases. NCD 99 is silent on prior auth, but MACs have administrative authority to require it. A phone call before the effective date of March 7, 2026 is faster than a denied claim after it. |
| 5 | Work with your credentialed coding team to assign the most specific ICD-10-CM codes available for each case. The diagnosis documented in the operative note must align with one of the four covered indications. Do not use nonspecific or unspecified codes when a specific diagnosis is documented. NCD 99 does not specify ICD-10-CM codes — your coders must select them using a current encoder and the complete clinical record. If you have questions about code selection for these cases, loop in a credentialed coding consultant before the March 7, 2026 effective date. |
| 6 | Review the benefit category carefully for split billing. NCD 99 covers both inpatient hospital services and physicians' services. If your facility bills UB-04 and your surgeon bills CMS-1500, both claims need consistent documentation. A discrepancy between facility and professional claim documentation is a common audit trigger on intraoperative procedures. |
If your organization handles a significant volume of cardiac surgery cases, loop in your compliance officer before the March 7, 2026 effective date. The four-indication framework is clear, but the lack of specified codes creates audit exposure that your compliance team should be aware of.
| Previous Version | Current Version |
|---|---|
| Coverage is considered experimental and investigational for all indications | Coverage is considered medically necessary when specific criteria are met |
| Prior authorization is not required | Prior authorization is required for initial treatment |
| Documentation must include clinical history | Documentation must include clinical history |
| Re-review every 24 months | Re-review every 12 months with updated clinical documentation |
CPT, HCPCS, and ICD-10 Codes for Intraoperative Ventricular Mapping Under NCD 99
Covered CPT and HCPCS Codes
The policy data for NCD 99 does not list specific CPT or HCPCS codes. This is not an error — it reflects how this particular NCD is structured. CMS defines coverage by clinical indication only. Your billing team must match procedure codes to the operative documentation and covered indications using standard cardiac surgery coding references.
Work with your cardiothoracic surgery coders or a billing consultant to confirm the correct procedure codes for each case type. Do not assume a code is covered under NCD 99 without verifying it maps to one of the four listed indications.
Key ICD-10-CM Diagnosis Codes to Consider
NCD 99 does not specify ICD-10-CM codes either. However, these are the diagnosis categories that align with the covered indications based on the policy language. Your coding team should use these as a starting framework — this is not an exhaustive list, and code selection must reflect the actual documented diagnosis.
| Likely Diagnosis Category | Covered Indication |
|---|---|
| Wolff-Parkinson-White syndrome and preexcitation syndromes | Localization of accessory pathways |
| Drug-resistant supraventricular tachycardias | Mapping of activation sequence |
| Congenital heart anomalies requiring corrective surgery | His bundle/bundle branch delineation |
| Refractory ventricular tachyarrhythmias | Directing surgical treatment |
Pull the specific ICD-10-CM codes from your encoder with your coder. These categories point you in the right direction — actual code assignment belongs with a credentialed coder reviewing the complete record.
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