Are you asking in regards to the 2016 AGI for verifying for efiling? Your only options are to use either the 2016 AGI or your Self-Select PIN from last year (the one where you chose the 5 digits.) You have to use one or the other in order to efile. The exception would be if you filed real late in the year, such as November 2017 or later. In that case one could use an AGI of 0 for efiling.
You could see if you can download your 2016 tax return transcript from the IRS website to get the AGI. It's a very sensitive document so you have to be careful with it. If you don't qualify to download one there, you can order one to come by postal mail, which takes 5-10 calendar days.
<a rel="nofollow" target="_blank" href="
http://www.irs.gov/Individuals/Get-Transcript">http://www.irs.gov/Individuals/Get-Transcript</a>
