My son is 18 and a full-time student. He doesn't have a 1098-T form from his college. How do I enter his student status into TurboTax and get the $2000 tax credit?

What 2,000 dependent credit do you mean? 

There are two Education Credits, but you need education expenses to claim either credit. 

You can enter the books and supplies as expenses you paid in the Education Section by selecting that you have an exception from receiving a 1098-T, but you need the EIN of the school. The school should be able to give you that number. 

The amount you paid for books and supplies most likely won't get you 2,000 worth of credit, but might give you something.  

If you mean the "Child Tax Credit" you son is too old for you to get that credit. 

If you mean something else, please continue the question. 

For most undergrads, the maximum tuition credit is $2500 ($1000 is refundable).

My understanding of the California "Promise Grant"  is that it is a tuition waiver, as opposed to a traditional scholarship.  So, essentially there was no tuition paid and none can be claimed for the tuition credit.

However books and computers and other required "course materials" are qualified expenses, The credit is 100% of qualified expenses, up to $2000; then 25% of the next $2000.

In the TT educational expenses  interview, answer no when asked if you got a 1098-T. Answer yes when asked if you qualify for an exception.  That should get you the screen to enter your expenses. Answer to the book expenses question.  Enter any computer cost as part of books not required to be purchased from the school, not in the computer box (it's a TT glitch).