I believe what will happen is that you will get a pro-rata credit towards the purchase of a new pass. For example, let say you paid $250 for this 5 day hopper, and have used 3 days. You have two remaining, meaning you'd get a $100 credit towards the purchase of a new pass. The credit is based on what you PAID for the pass(this is important especially if you bought the pass a few years ago), not the going rate of passes today. Now, I could be wrong here, but if I am, someone will correct me.