Couple questions about 529 plan withdrawals

It varies by school. The 529 spending for room and board is only considered qualified if it is not more than the higher of either:

-The allowance for room and board, as determined by the eligible educational institution, that was included in the cost of attendance (for federal financial aid purposes) for a particular academic period and living arrangement of the student.

or

-The actual amount charged if the student is residing in housing owned or operated by the eligible educational institution.

So if the school’s allowance for off-campus room and board is $12k, and the student living off campus takes $13k in 529 distributions to pay rent and buy food, there will be $1k in non-qualified 529 distributions where the earnings portion will be subject to income tax and the additional 10% penalty.