I am a non-resident alien in F-1 status. I have item AA on my W2. Do I have to put it in the electronic W2 form on turbotax or not reporting it doesn't affect anything?

As a F-visa holder, you are considered as a nonresident for five years from the year you first enter.  If you are a nonresident alien, you cannot file with TurboTax.  As TurboTax does not support any nonresident tax forms, you are advised to contact Sprintax which is affiliated with TurboTax to assist our international students and nonresident aliens customers with their US tax returns.  

If you are a resident alien, you will report your Form W--2 information the exact same way how it is reported on the hardcopy including the AA in Box 12. Do not change or edit any information.  Please see attached screenshot.