If a student staying in a dorm is required to pay $10k in advance, in September, for the entire 2018-19 school year of room and board, can they count the entire $10k as their qualified "room & board" expense and take a matching $10k distribution from their 529 account? Or is the qualifying part only the pro-rated Sep-Dec portion of the $10k, and the remainder is a qualifying expense of the 2019 year even though actually paid in 2018?
Is there any source document/link that would confirm the correct treatment?
Thank you for your advice,
MK