@cyndee5101 - Yeah, In your situation if you are worried you might spend it, I would just put it in a 12 month CD that will mature at tax filing time next year. The ONLY reason to pay it early would be if you think it might not be available when you need it for whatever reason.
But its not as hard to calculate as people think, just take your tax bracket on AGI and multiply that by whatever you haven't paid back yet.
