When you are entering your education expenses you will be asked if you used a 529 plan to pay for the expenses. If you answered YES, in the next couple of screens you will be given the opportunity to enter the Room and Board expenses.
To enter the education expenses, you would:
There is no place to enter room and board, so what Turbo Tax worksheet do I have to go to?
That is the problem with TT - not enough detail provided in the step through.
Assuming the student is your dependent and you are the recipient of the 1099-Q:
Enter the 1099-Q before you enter the 1098-T. TurboTax will only give your the R&B screen if it knows you have a 529 plan distribution. Later, in the 1098-T (educational expenses and scholarships) interview, answer yes when asked if you have book expenses. That screen includes the box to enter Room & Board.
For you to enter room and board as a qualified education expense that was paid for with a 529 plan distribution, you must first enter the 1099-Q for the student.
To enter the 1099-Q in TurboTax Online:
Once you enter the 1099-Q, you will go back and edit the education expenses for the student.
To enter the education expenses:
Please note, the 529 Plan withdrawal only needs to be reported on the tax return of the person whose SSN is on the form if the withdrawal is more than the tuition paid in Box 1 of the 1098-T and other adjusted qualified educational expenses.
Please review the TurboTax article Guide to IRS Form 1099-Q: Payments from Qualified Education Programs for further details.