When processing claims for Medicare Part B drugs where an Express Script’s commercial or EGWP plan is the secondary payer, messaging may indicate the member has other coverage through Medicare Part B or Medicare Advantage. In this instance the claims will reject with NCPDP reject code A6 "This Product/Service May Be Covered Under Medicare Part B" and 41 "Submit Bill To Other Processor Or Primary Payer." When this occurs please process the claim with Medicare Part B as the primary payer. If the claim rejects and secondary messaging indicates COB may be required, please use the following process.

*Please see attached for more information.