I believe that TurboTax only keeps 3 years of prior year returns available for download/update. So currently that would be 2014, 2015, 2016.
https://ttlc.intuit.com/questions/4133925-can-i-download-the-turbotax-2013-software-the-past-product...
♪♫•*¨*•.¸¸♥Lisa♥ ¸¸.•*¨*•♫♪
