With federal unsubsidized loans and all private student loans, you'll have to pay the interest that accumulates while you're in school. But unless your private loan repayment plan requires payments during school, you don't need to pay any of it while you're still in school.[1,2] If you can afford it, though, it may make sense to make interest-only payments to avoid having the interest capitalized when you graduate and added to your loan balance.[9]