Qualified education expenses paid in 2017 for an academic period that begins in the first 3 months of 2018 can be used in figuring an education credit for 2017 only. See Academic period, earlier. For example, if you pay $2,000 in December 2017 for qualified tuition for the 2018 winter quarter that begins in January 2018, you can use that $2,000 in figuring an education credit for 2017 only (if you meet all the other requirements).
You cannot use any amount you paid in 2016 or 2018 to figure the qualified education expenses you use to figure your 2017 education credit(s).
如果用了student loan 付了部分学费，是不是算qualified paid tuition? 发现这一部分是学校在2018年自动付的。谢谢！