Extracorporeal Membrane Oxygenation (ECMO) — CPB 0546 | AETNA Coverage Update

Aetna modified CPB 0546 for Extracorporeal Membrane Oxygenation (ECMO), effective September 26, 2025. Here's what billing teams need to do.

Aetna, a CVS Health company, updated its ECMO coverage policy under CPB 0546, affecting a broad set of CPT codes including 33946, 33947, 33948, and 33949 for physician management, plus the full cannula insertion, repositioning, and removal code families (33951–33989). This is a high-exposure policy. ECMO claims carry significant reimbursement value, and a documentation gap or wrong medical necessity designation will produce a claim denial that's hard to reverse.

Quick-Reference Table

Aetna ECMO Coverage Criteria and Medical Necessity Requirements 2025

The Aetna ECMO coverage policy under CPB 0546 ties coverage directly to medical necessity criteria. Aetna considers ECMO medically necessary when specific selection criteria are met. No selection criteria, no coverage — it's that clean.

The covered CPT codes split into two functional categories. The first is physician services: CPT 33946 (ECMO/ECLS initiation, veno-venous), 33947 (initiation, veno-arterial), 33948 (daily management, veno-venous), and 33949 (daily management, veno-arterial). These are the codes your intensivists and cardiothoracic surgeons will bill daily during an ECMO run.

The second category covers procedural services — cannula insertion, repositioning, and removal across age bands and access approaches. Aetna draws explicit distinctions between percutaneous and open approaches and between pediatric patients (birth through five years) and older patients (six years and older). That age split matters for code selection. Billing 33951 when you should bill 33952, or vice versa, will trigger a medical necessity mismatch on review.

Prior authorization is a near-certainty on ECMO cases given the cost and complexity. Verify prior auth requirements with your Aetna provider relations contact before the first cannula goes in. Waiting until the patient is on circuit is too late.

Reimbursement under this policy is meaningful — ECMO runs can last days or weeks, and the daily management codes (33948 and 33949) stack per day. A documentation failure that voids medical necessity on day one can cascade backward through the entire run.

Aetna ECMO Coverage Criteria and Medical Necessity: Coverage Indications at a Glance

The policy summary confirms that Aetna considers ECMO medically necessary when selection criteria are met. The table below reflects the coverage structure as defined in CPB 0546.

Aetna ECMO Billing Guidelines and Action Items 2025

ECMO billing is complicated under any payer. Under this updated CPB 0546, the margin for error is smaller. Here are the steps to take before you submit a claim with a date of service on or after September 26, 2025.

1. Pull the updated CPB 0546 policy and read the selection criteria. The policy confirms medical necessity coverage when selection criteria are met — but the specific clinical thresholds in the full policy document are what Aetna's reviewers will use. Make sure your clinical documentation team has those criteria in hand. If your hospital's case management team isn't aligned with the updated CPB 0546 requirements, fix that now.

2. Verify age-band code selection on every ECMO case. Aetna's ECMO billing guidelines distinguish between birth–five years and six years and older across insertion (33951–33956), repositioning (33957–33964), and removal (33965–33986) codes. Pediatric ECMO cases are especially vulnerable to upcoding or downcoding errors on age. Build an age-verification step into your charge capture workflow.

3. Separate veno-venous from veno-arterial on every case. CPT 33946 and 33948 are veno-venous; 33947 and 33949 are veno-arterial. These are not interchangeable. Your charge capture template should hard-code this distinction so coders aren't selecting based on proximity in a dropdown.

4. Confirm prior authorization before circuit initiation. ECMO authorization often happens on an emergency basis, but that doesn't mean you skip the step. Document every prior auth attempt — date, time, Aetna reference number, outcome. A missing prior auth record is a clean-claims killer on cases this expensive.

5. Bill daily management codes (33948 or 33949) with daily supporting documentation. Each day on circuit needs its own documentation of medical necessity. Don't let the team assume that one strong admission note carries through a 14-day run. Aetna can and will deny individual days if the clinical record doesn't support continued ECMO.

6. Review related procedure codes for bundling risks. CPB 0546 includes a substantial list of related CPT codes — lung transplant codes 32851–32854, CABG codes 33510–33536, valve procedures, and septal repairs. If your team bills ECMO alongside any of these, audit for bundling edits before submission. Some of these procedures involve cardiopulmonary bypass, which creates legitimate overlap questions.

7. Flag any ambiguous cases for compliance review. ECMO cases that don't fit cleanly into the stated selection criteria need eyes from your compliance officer before you submit. The dollar amounts on these claims make them audit targets. If you're unsure, loop in your compliance officer or billing consultant before the effective date applies to a claim you're holding.

CPT, HCPCS, and ICD-10 Codes for ECMO Under CPB 0546

Covered CPT Codes — ECMO/ECLS Physician and Procedural Services (When Selection Criteria Are Met)

Other CPT Codes Related to CPB 0546 (Cardiac, Thoracic, and Vascular Procedures)

These codes appear in the CPB 0546 Aetna policy as related procedures. Many involve cardiopulmonary bypass and may appear on the same claim as ECMO codes. Review for bundling rules.

The full policy includes 110 CPT codes and 158 ICD-10-CM codes. Access the complete list at CPB 0546 on PayerPolicy.

Key ICD-10-CM Diagnosis Codes

The full CPB 0546 policy includes 158 ICD-10-CM codes covering the range of diagnoses that support ECMO medical necessity — including acute respiratory failure, cardiogenic shock, congenital cardiac anomalies, and post-cardiotomy cardiac failure. The full ICD-10 list is available in the policy source document. Your coding team should map every ECMO case to a supporting ICD-10 from the covered list before submitting.