If you pay any qualified tuition amount out of the pocket during 2017 and did not receive a Form 1098-T, you can still claim an education credit.
In TurboTax online edition, here are the steps:
1. After sign into your account and select Take me to my return
2. At the right upper corner, in the search box , type in 1098t and Enter
3. Select Jump to form 1098T
4. On screen, "Do you want to enter your higher education expenses?" answer Yes.
5. Go through the step-by-step interview questions
6. On screen, "Did you get a 1098-T from school for 2017?" answer No
7. Follow prompts, on screen, You'll need to enter Federal ID number, select I can't find the ID no to continue to enter your expenses.
See attached screenshot.