I was able to lock in a low interest rate with a private loan servicer when I finished in 2005. (studentloanhero.com)
In addition, since many closed mortgages are also fixed - rate mortgages, locking in a low interest rate for the entirety of your loan can mean even more money saved. (superbrokers.ca)
But if you only want to lock in a lower interest rate on your mortgage and don't need the cash, regular refinancing makes more sense. (nerdwallet.com)