You need to do two main things.  The first is to contact Sallie Mae and let them know that your signature was forged and you did not consent to liability on the loan.  As with a forged check, you also need to file a complaint with your local law enforcement.  You can submit a copy of the complaint to Sallie Mae as well as additional verification that you did not consent to this use of your name, signature, or identification.  This seems a bit harsh to press charges on your dad-- but it's just as harsh that your dad put you in this situation.A secondary option is to sue your dad and get him to take out another loan in his name only and get the Sallie Mae loan paid off and discharged.  With the discharge of the loan, you're off the hook for any potential future indebtedness.