In TurboTax (TT), enter at:
Federal Taxes Tab (Personal for H&B version)
Deductions & Credits
“I’ll choose what I want to work on” button
-Scroll down to:
--Education
--ESA and 529 Qualified Tuition Programs (1099-Q)
When you fail to enter any offsetting expenses, TurboTax will treat all the earnings (box 2 of the 1099-Q) as taxable and calculate the 10% penalty on form 5329.