(CNN) -- You better use your Delta Sky-Miles while you can.
Under new rules that went into effect this month -- your miles will die when you do.
Delta's policy used to allow members to leave their miles to family or friends.
A spokeswoman for the Atlanta-based carrier says the bonus miles are intended to reward those who participate in the program.
United, Southwest and JetBlue already have similar rules in place.
On the positive side, Delta Sky-Miles never expire -- as long as you are alive.