On the Free Application for Federal Student Aid, EFC stands for the expected family contribution. If the EFC is zero, the calculation has determined that this particular family is not expected to make any financial contribution toward college expenses.
The expected family contribution is calculated by factoring several aspects of the financial profile of the student's family. The family's income from all sources is weighed against the family size and number of family members attending school. Schools consider the expected family contribution when calculating the size of award they plan to offer the student in financial assistance. Students with a large expected family contribution are expected to require less financial assistance.