Amtrak Guest Rewards program members who take two roundtrips on Acela Express or Metroliner between select city pairs will earn a free roundtrip. Members need only register online at http://www.Amtrak.com, make sure to include their Guest Rewards with the reservations, and take as many trips as possible.

Members have until May 31 to take qualifying travel. Then, 6-8 weeks later, Amtrak will send an earned voucher or vouchers good for a free Acela Express/Metroliner trip any time between June 15 and Dec. 15.

In addition, when you pay for your Acela Express/Metroliner select city pair travel with a MasterCard card, you’ll earn double points.