As I indicated in my answer, I assumed you were asking about the education credits - the American Opportunity Credit or the Lifetime Learning Credit. The rules for a 529 plan are different. That might be why you are confused about what are qualified expenses. Room and board can be qualified expenses for a 529 plan, with some restrictions. For details, see "Qualified education expenses" on pages 56-58 of Publication 970, at the link that I gave you above.
(The 2017 edition of Pub. 970 is not available yet. The link will give you the 2016 edition, and the page numbers that I referred to are for the 2016 edition. There are no changes for 2017 regarding 529 plans or the two credits that I mentioned, except inflation adjustments of the income limits for the credits. However, the Tuition and Fees deduction is not available for 2017.)
