After you file

Do you need to prepare and file prior year returns?  

You can only do the last 3 years with Turbo Tax.  Online is only good for the current year.   You have to buy each year separately.  You can buy the last 3 years of Turbo Tax here,

https://turbotax.intuit.com/personal-taxes/past-years-products/

You will need a full Windows or Mac to install it on.

 

How to prepare a prior year return

https://ttlc.intuit.com/community/using-turbotax/help/how-do-i-prepare-a-prior-year-tax-return/00/25...