Federal Perkins Loan has a fixed 5-percent interest rate that does not change during the 10-year repayment schedule. Similar to other loans, there is a grace period after no longer being enrolled at least half-time, but it is longer than most: nine months instead of six. Students that apply for the Perkins Loan are eligible to receive a maximum of $60,000 if they attend graduate school, and $27,500 if they do not.