To e-file your 2018 return you need your 2017 AGI (not that you got a refund or not). If you did not file a 2017 return, then enter zero for the 2017 AGI. If you did file a return in 2017, you will find your 2017 AGI on your originally-filed 2017 tax return, form 1040 (Line 37), 1040A (Line 21), 1040EZ (Line 4), 1040NR (Line 36), Form 1040X (Line 1, column A).
If you cannot get your 2017 AGI you would need to mail in your return.
How do I find last year’s AGI?
