The federal government assumes two things- 1)Your parents will give you some support for undergrad and 2)Your parents will give you no support for graduate school. For that reason, it's fine to have no EFC now if you're still in undergrad because there's no assumption that your parents are going to continue to support you in law school. If you have no EFC, you'll have a chance to qualify for both the Stafford and the Perkins, so why not fill it out for yourself only to maximize your chances of getting loans with the most favorable rates?