If you used the CD/Download version, you need to view your saved returns for the last 3 years that have the file ending in .tax20XX (correct year) or the pdf file saved on your computer or backup. Search your computer for all files ending in .tax. Check in One Drive, Drop Box etc. it should be in your Documents then in the Turbo Tax folder. You can also try this, start the program, then go up to File-Open and see if it finds your file.
If you are unable to locate your files, see the alternative ways to locate your AGI on the IRS website here: Validating Your Electronically Filed Tax Return
To find your AGI, please see the following TurboTax FAQ's:
How do I find last year’s AGI?
Why can't I find my return in Tax Home or My Docs™?
The amount can be located on:
Form 1040 - Line 38
Form 1040A - Line 21
Form 1040EZ - Line 4
