For tax year 2018 the AGI is on Form 1040 Line 7.
Click on Tax Tools on the left side of the screen. Click on Tools. Click on View Tax Summary. The 2018 will be shown
For tax year 2017 -
- Form 1040 – Line 37
- Form 1040A – Line 21
- Form 1040EZ – Line 4
Or -
To access your current or prior year online tax returns sign onto the TurboTax website with the userID you used to create the account - https://myturbotax.intuit.com/
Scroll down to the bottom of the screen and on the section Your tax returns & documents click on Show. Click on the Year and Click on View adjusted gross income (AGI)
You can also get free transcripts of your federal return from the IRS - http://www.irs.gov/Individuals/Get-Transcript