If you mean "previous" as in other years...not for 2018...
1) Yes....IF you did not file any tax returns for a prior year (meaning 2017 or earlier), and you have one or more W-2 forms for that year, you can prepare them and "mail" them in (no e-filing allowed for any year but 2018 right now..and that ends in mid-October). For the prior year's forms, you have to buy , download and install each year involved separately on a full MAC or Windows computer. Only software back to 2015 is available, (Window 7 or higher works for all years...if for a MAC...depends on what version you are using)
https://turbotax.intuit.com/personal-taxes/past-years-products/
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2) Yes...If you already filed taxes for any of those prior years, and did not include the W-2 forms in question, then you have to amend the appropriate year's forms and mail in the amendment forms.
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3) NO...you cannot include a 2017..or earlier year W-2 in your 2018 tax returns
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
