I have a student loan interest form I forgot to add to my taxes. I have not mailed them yet, but I can't seem to access my info to add it so that I can change it.

[TomK]

Since you have already printed your return and are about to mail it, TurboTax entry screens will change.  In order to get into your tax return, you will need to do the following: 

1. Log in.
2. Click on Add state on your Timeline (you will not be adding it - just a workaround). 
3. You will then be allowed back in to your return where you can add the 1098-E (student loan interest) as per the instructions below.

If you have already filed your return, then you will need to amend it:
https://ttlc.intuit.com/replies/3288565

To enter your student loan interest (even if you didn't get a 1098-E from your lender):

1. Log into your account and continue (if not already there).
2. In the Search box (top right-hand corner), type “1098-E”.
3. Click on the Magnifying Glass icon.
4. Click on “Jump to 1098-E” link high-lighted in Blue.
5. Answer Yes to the question “Did you make any student loan payments?”
6. Answer the Step-by-step instructions.

[Edited on 2/21/17.]