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Access to prior year returns.

https://ttlc.intuit.com/community/prior-year-return/help/how-do-i-access-my-prior-year-return/00/270...

You can get a free transcript from the IRS:   

https://www.irs.gov/individuals/get-transcript

How do I get a copy of a return I filed using online TurboTax?

https://ttlc.intuit.com/questions/1900748

How do I get a copy of a return I prepared using desktop TurboTax?

https://ttlc.intuit.com/questions/1900639

How to upgrade to PLUS

How do I purchase TurboTax PLUS so I can get my .tax file?

In TurboTax Free Edition, you can purchase PLUS to unlock your prior-year .tax file.

The exact instructions will vary depending on the status of your 2018 TurboTax Online return (select one):

• I haven't started a 2018 return yet
• I started a 2018 return but haven't filed it yet
• I've already filed my 2018 return

Note:  While you still can, print a copy of your current year tax return and save it as a pdf, too.  That way you will have it when you need it for school, a loan, etc. without going through a lot of aggravation to get it.