If you used TurboTax Online, sign in to TurboTax Online for the tax year 2018 here: https://ww1.2018.turbotaxonline.intuit.ca/.  If you used TurboTax CD/Download and you saved it on your computer you can simply go to the Start button on the bottom left of your screen and click on Start and you will see a small search bar - type in .tt18 and you will find it there.  If you did not save it, unfortunately, there is not a way to access it. 

I saved my 2018 return im trying to get back to the file please help me brian

I need my agi from 2018 tax return I entered 481 and it says its wrong

@Gaby6767 and @Oneguy44 Please refer to TurboTaxMary-Ann1’s response above. If you are still not able to find your return, please give us some more details about your problem such as what version of TurboTax you are using, is it Online or CD/Download. You can post to a new thread here: https://turbotax.community.intuit.ca/community/forums/postpage/board-id/260

@Coryshelhorse12 If you need assistance with U.S. versions of TurboTax, please visit: https://ttlc.intuit.com/