You can pre-order a 2017 desktop edition as a download for a Mac OS from this TurboTax website - https://turbotax.intuit.com/personal-taxes/cd-download/
The prior tax year tax data file, .tax2016, can be transferred to the 2017 TurboTax desktop program when a new 2017 tax return is started. The tax data file created using the TurboTax program for Windows can be transferred to the TurboTax program for a Mac, and visa-versa.