Hi John, it actually applies until final payment. I've done this many times. Sometimes months after booking. If your category (it would have to be the same room type) reduces in price then they reduce your fare. As long as you haven't paid it off in full, or final payment hasn't come up they will indeed lower the fare. But as another poster said, you have to watch and then contact them or if you booked through a Travel agent, then call them. The cruise line won't automatically reduce it. There are some travel agents that advertise that they will do this for you. But there are websites like cruise watch that will notify you as well.