Even though you are positive you are using the AGI that is shown on your 2018 return,
if you filed late or amended your return, your correct 2018 AGI may not be in the system. You can try using zero as the AGI instead. If zero will not let you e-file, then you have to print, sign and mail your return. Your TurboTax fees must be paid in order to print.
https://ttlc.intuit.com/questions/1944348-how-do-i-print-and-mail-my-return-in-turbotax-online
Note: If you mail your federal return, you will also need to mail your state return. You will not be able to e-file your state return.
https://ttlc.intuit.com/questions/3415597-what-if-i-entered-the-correct-agi-and-i-m-still-getting-an...
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
