Can I pay my student loan all at once?

I have a federal stafford student loan I need to start paying in June,but the interest is over $1,200 on a $3850 loan!The rate is only 6.8%,but it's over $1200 after all is said and done.I want to just pay it off to avoid the interest.Do I still have to pay the interest now? I'm ready to just cut them a check for $3850,cause I have it.I don't want to pay that much interest.Any advice?Thanks