Graduate PLUS loans are designed for graduate and professional students who want a low-cost loan backed by the federal government. You can borrow up to the cost of attendance, as determined by the school, minus any other financial aid you're receiving. You have to be enrolled at least half time in a degree program, have a valid Social Security number and be a U.S. citizen or eligible permanent resident to qualify. When it comes to repaying the loan, you have up to 10 years to do it, and you must pay at least $50 a month. There's no penalty for early repayment.