can I pay off the reverse mortgage after 3 years

Yes, you can.

If you have an ARM reverse mortgage with a LOC(line of credit) you should keep it "open" by paying it down to $100. Also of great value is that by paying down the Reverse Mortgage balance you will increse the LOC by that very same amount and it will continue to "grow" at the componding rate (interest rate+ 1.25%) making it available for future use. It is "open-ended" credit meaning you can borrow from it, pay it down, and borrow from it again without restriction. In addition it is secure, in that the LOC is not capped, reduced, frozen, or eliminated because of deteriorating market conditions or property value declines. Of course every situation is unique, so in the end it depends on what you are trying to accomplish.

Yes you can pay off a reverse mortgage anytime and there will be no pre-pay penalty.