Yes you can. The returns are filed separately. You can use either the online or cd/download version of TurboTax to file 2017. To file the 2016 return, you will need to use the cd/download version of TurboTax.
See links below that provide a link and comparison of all TurboTax current year products:
Desktop
product comparison
Online
Product Comparison
See the TurboTax FAQ link below that explains how to file your prior year return (2016):
https://ttlc.intuit.com/replies/3301770
