← Back to list
Open and Thoracoscopic Approaches to Treat Atrial Fibrillation and Atrial Flutter (Maze and Related Procedures)
Effective date
Not stated in the notice
Identified
Jun 20, 2026
Summary
BCBSMS considers the maze or modified maze procedure, performed on a non-beating heart during cardiopulmonary bypass with concomitant cardiac surgery, medically necessary for the treatment of symptomatic atrial fibrillation or flutter. Stand-alone minimally invasive, off-pump maze procedures, including those done via mini-thoracotomy, are considered investigational, as is hybrid ablation (a combined percutaneous and thoracoscopic approach). An open maze or modified maze performed on a non-beating heart during cardiopulmonary bypass without concomitant cardiac surgery is also considered investigational.
Get alerts when payers change rules like this one
We check Blue Cross & Blue Shield of Mississippi and other payers every day and email you when a change matches your specialty and state.
Get Blue Cross & Blue Shield of Mississippi alertsPolicy Monitoring is free. No card required.
What to do
Action · 4 steps
01Billing team: Bill CPT 33256, 33257 and 33259 for maze procedures only when the procedure is performed according to the policy's medically necessary statement, because the listed codes are only medically necessary if the procedure is performed according to the Policy section.
02Billing team: Note that CPT 33254, 33255, 33258, 33265 and 33266 are listed as investigational codes in this policy.
03Billing team: Document that the service is medically necessary, because BCBSMS makes no payment for services not documented to be medically necessary, and a physician's order or recommendation does not in itself make a service medically necessary.
04Billing team: Expect that performing the maze procedure without concomitant cardiac surgery should rarely be needed, given the less-invasive alternatives covered in the Catheter Ablation as Treatment for Atrial Fibrillation policy.
Codes mentioned
3325633257332593325433255332583326533266I48.0I48.11I48.19I48.20I48.21I48.91I48.3I48.4I48.92
Original notice
Open and Thoracoscopic Approaches to Treat Atrial Fibrillation and Atrial Flutter (Maze and Related Procedures)
bcbsms.com · Always check the source before changing claims.
Related changes
See all Blue Cross & Blue Shield of Mississippi changes →Catheter Ablation as Treatment for Atrial FibrillationMediumNo effective date · Medical PolicyPercutaneous Left Atrial Appendage Closure Devices for Stroke Prevention in Atrial FibrillationMediumNo effective date · Medical PolicyTelehealth: Remote Patient Monitoring ServicesMediumEffective Jan 1, 2026 · Medical PolicyBrowse every Blue Cross & Blue Shield of Mississippi change in the policy list