As long as you are able to use the W/D for the AOTC or Lifetime learning credit, the distibution and expenses don't have to happen in the same calendar year. If you don't qualify for the credit, such as if MAGI is too high, then all expenses would have to happen in the same calendar year as the 529 distribution for them to be tax free.
You would not have to include the 1099-Q with the return if all the expenses were qualified, but they are not qualified if they dont line up in the same calendar year as distribution, with the exception of qualified AOTC and Lifetime Learning related expenses.
