TL;DR: The Centers for Medicare & Medicaid Services modified NCD 99 governing intraoperative ventricular mapping coverage, with an effective date of March 7, 2026. This policy does not list specific CPT or HCPCS codes, so your billing team needs to confirm code mapping independently before submitting claims.
CMS intraoperative ventricular mapping coverage policy under NCD 99 in the NCD Medicare system covers this cardiac electrophysiology technique for four specific indications only. If your facility performs intraoperative ventricular mapping for anything outside those four conditions, expect a claim denial. Here's what billing teams need to know before March 7, 2026.
Quick-Reference Table
| Field | Detail |
|---|---|
| Payer | CMS (Centers for Medicare & Medicaid Services) |
| Policy | Intraoperative Ventricular Mapping — NCD 99 |
| Policy Code | NCD 99 |
| Change Type | Modified |
| Effective Date | 2026-03-07 |
| Impact Level | Medium |
| Specialties Affected | Cardiac surgery, electrophysiology, congenital heart surgery, cardiothoracic surgery |
| Key Action | Confirm your intraoperative ventricular mapping billing maps to one of the four covered indications before submitting Medicare claims after March 7, 2026 |
CMS Intraoperative Ventricular Mapping Coverage Criteria and Medical Necessity Requirements 2026
NCD 99 is the National Coverage Determination governing Medicare coverage of intraoperative ventricular mapping. This technique records cardiac electrical activity directly from the heart during surgery. A surgeon uses a probe with electrodes to explore epicardial, intramural, and endocardial sites, generating a map of the electrical activation sequence. That map guides the surgeon to the precise site requiring intervention.
The CMS coverage policy is narrow and explicit. Medicare covers intraoperative ventricular mapping for exactly four indications. If your documentation doesn't tie the procedure directly to one of these four conditions, you don't have a covered claim — full stop.
The four covered indications under NCD 99:
| # | Covered Indication |
|---|---|
| 1 | Localizing accessory pathways associated with Wolff-Parkinson-White (WPW) syndrome and other preexcitation syndromes |
| 2 | Mapping atrial and ventricular activation sequences for drug-resistant supraventricular tachycardias |
| 3 | Delineating the anatomical course of the His bundle and/or bundle branches during corrective cardiac surgery for congenital heart diseases |
| 4 | Directing surgical treatment for patients with refractory ventricular tachyarrhythmias |
Medical necessity under this policy is tied directly to those four conditions. A claim that lists intraoperative ventricular mapping without documentation anchoring it to one of these specific diagnoses will fail medical necessity review.
This is a tight coverage policy. CMS is not covering intraoperative ventricular mapping as a general surgical adjunct. It's covered as a targeted diagnostic tool for specific, well-defined cardiac conditions. Your operative notes and supporting documentation need to make that connection explicit.
The policy applies under two Medicare benefit categories: Inpatient Hospital Services and Physicians' Services. Both the facility and the professional component are in scope.
Prior authorization requirements are not explicitly stated in this NCD. However, that doesn't mean you're in the clear. Your Medicare Administrative Contractor may impose additional local requirements. Check with your MAC before the effective date if you're billing this in high volume.
Whether intraoperative ventricular mapping is covered under Medicare for anything outside these four indications? The answer is no. The NCD is specific. Off-label use of this mapping technique does not get you to reimbursement under Medicare.
CMS Intraoperative Ventricular Mapping Exclusions and Non-Covered Indications
NCD 99 doesn't include a separate list of explicitly excluded indications. But the coverage structure itself creates a de facto exclusion list. Any use of intraoperative ventricular mapping that falls outside the four covered indications is not covered.
Practically speaking, this means intraoperative ventricular mapping performed as exploratory, elective, or diagnostic mapping outside the four conditions will not meet medical necessity under this coverage policy. Document carefully. If a claim comes back denied and your operative note doesn't anchor the procedure to one of the four covered conditions, you have no recourse under NCD 99.
Coverage Indications at a Glance
| Indication | Status | Relevant Codes | Notes |
|---|---|---|---|
| Localizing accessory pathways — Wolff-Parkinson-White (WPW) and other preexcitation syndromes | Covered | Not specified in NCD | Documentation must confirm WPW or preexcitation diagnosis |
| Mapping atrial/ventricular activation for drug-resistant supraventricular tachycardias | Covered | Not specified in NCD | "Drug-resistant" must be documented — prior treatment failure required |
| Delineating His bundle and/or bundle branch course during corrective cardiac surgery for congenital heart disease | Covered | Not specified in NCD | Applies specifically in the context of corrective congenital surgery |
| Directing surgical treatment for refractory ventricular tachyarrhythmias | Covered | Not specified in NCD | "Refractory" must be supported by documentation of failed prior treatment |
| Any use outside the four indications above | Not Covered | N/A | No Medicare reimbursement available under NCD 99 |
Two words in this table carry significant billing weight: "drug-resistant" and "refractory." CMS is not covering mapping for tachycardias or tachyarrhythmias that haven't already failed medical management. Your documentation needs to show prior treatment attempts and failure. If that's missing from the record, your claim is vulnerable.
CMS Intraoperative Ventricular Mapping Billing Guidelines and Action Items 2026
This policy's effective date is March 7, 2026. Here's what your billing team needs to do before and after that date.
| # | Action Item |
|---|---|
| 1 | Audit your current charge capture for intraoperative ventricular mapping before March 7, 2026. Pull claims from the past 12 months. Confirm each one maps to a documented covered indication. Identify any claims where the covered indication isn't explicit in the operative note or diagnosis coding. Fix your charge capture workflow now. |
| 2 | Work with your clinical documentation team to strengthen operative note language. The terms "drug-resistant," "refractory," "WPW," "preexcitation syndrome," and "congenital heart disease corrective surgery" need to appear explicitly in the operative record. Vague language like "tachycardia" without qualification won't hold up in a medical necessity review. |
| 3 | Confirm CPT code mapping with your MAC. NCD 99 does not list specific CPT or HCPCS codes. This is a real gap in the policy data. Contact your Medicare Administrative Contractor to confirm which codes are expected on claims for intraoperative ventricular mapping under NCD 99. Don't assume. Get it in writing. |
| 4 | Review your ICD-10-CM coding for alignment with covered indications. Your diagnosis codes on the claim need to support the covered indication. NCD 99 does not specify ICD-10-CM codes for any of the four covered indications. Have your coding team identify the correct diagnosis codes by consulting current ICD-10-CM references and any MAC-level guidance. This is where claim denial risk is highest — mismatched or unspecified diagnosis codes are the fastest way to lose reimbursement on an otherwise valid claim. |
| 5 | Talk to your compliance officer if you're performing intraoperative ventricular mapping for indications that don't cleanly fit the four covered uses. If your cardiac surgery program has gray-area cases — mapping performed in complex reoperations or for conditions adjacent to the four covered indications — get a compliance review before March 7, 2026. The billing guidelines here are narrow, and the financial exposure on denied inpatient claims is significant. |
| 6 | Check for MAC-level local coverage determinations. NCD 99 sets the floor. Your MAC may have issued an LCD or billing guidelines that add documentation requirements, prior authorization rules, or coding specifics on top of the NCD. Search your MAC's website for supplemental guidance tied to this procedure before the effective date. |
| 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 Codes (When Selection Criteria Are Met)
NCD 99 does not list specific CPT or HCPCS codes. This is an important gap in the policy document. Your coding team must identify the correct CPT and HCPCS codes by consulting your MAC or a qualified coding resource. Do not bill based on assumption.
| Code | Type | Description |
|---|---|---|
| Not specified in NCD 99 | — | Contact your MAC for applicable CPT/HCPCS codes |
ICD-10-CM Diagnosis Codes
NCD 99 does not list specific ICD-10-CM diagnosis codes. Your coding team must identify the appropriate diagnosis codes for each covered indication by consulting current ICD-10-CM references and MAC-level guidance.
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