If you used turbo tax in prior years you can access your AGI by following the instructions in our FAQ's link below:
https://ttlc.intuit.com/questions/3404575-how-do-i-access-my-prior-year-2016-return
You can also access a free transcript on the IRS website to get your 2016 AGI.
https://www.irs.gov/individuals/get-transcript