Effective February 1, 2019, Percutaneous Left Atrial Appendage Closure Devices for Stroke Prevention in Atrial Fibrillation (CPT code 33340) will no longer require prior authorization for BlueCHiP for Medicare, as the service will remain medically necessary when performed as part of a CMS-approved clinical trial. There will be no change to Commercial products; the service will continue to require prior authorization. View this version of the policy.