The Raiser's Edge 7.96 and future releases will be able to accommodate storing the new MasterCard sequence with no issue. 

In The Raiser's Edge 7.95 and prior, the Raiser's Edge will see this as an invalid number. In order to continue with saving the card, you can do the following:
  1. In the Raiser's Edge, navigate to Config > Business Rules > General
  2. Under "When saving a record with invalid credit card information...." select either "Display Warning" or "Save record anyway"
For users with The Raiser's Edge 7.95 and prior, you will be able to charge the new MasterCard numbers until June 2018.