There is a common situation, where you may actually want to pay some income tax on the 529 distribution. You can claim an education credit, even if the education expenses were totally paid with 529 funds.
You can and should claim the tuition credit before claiming the 529 plan earnings exclusion. The educational expenses you claim for the 1099-Q should be reduced by the amount of educational expenses you claim for the credit. You can not double dip. You cannot count the same tuition money, for the tuition credit, that gets you an exclusion from the taxability of the earnings (interest) on the 529 plan. Since the credit is more generous; use as much of the tuition as is needed for the credit and the rest for the interest exclusion. Another special rule allows you to claim the tuition credit even though it was "his" money that paid the tuition.
In addition, there is another rule that says the 10% penalty is waived if he was unable to cover the 529 plan withdrawal with educational expenses either because he got scholarships or the expenses were used (by him or the parents) to claim the credits. He'll have to pay tax on the earnings, at his lower tax rate (subject to the “kiddie tax”), but not the penalty.
Total qualified expenses (including room & board) less amounts paid by scholarship less amounts used to claim the Tuition credit equals the amount you can use to claim the earnings exclusion on the 1099-Q.
Example:
$10,000 in educational expenses(including room & board)
-$3000 paid by tax free scholarship
-$4000 used to claim the American Opportunity credit
=$3000 Can be used against the 1099-Q
Box 1 of the 1099-Q is $5000
Box 2 is $600
3000/5000=60% of the earnings are tax free
60%x600= $360
You have $240 of taxable income (600-360)
