When you have a disc drive and can actually install from the physical CD, the CD has the software for Mac or Windows. But the downloads are specific to either Mac or Windows. If you need to install to both Windows and Mac, you need help from customer support to get the right download.
To call TurboTax customer support
https://ttlc.intuit.com/questions/1899263-what-is-the-turbotax-phone-number
Customer support is available from 5 a.m. to 9 p.m. Pacific time daily
@xmasbaby0 - Thanks for the prompt reply. I did call customer support and lost one hour of my precious weekend time to hear that they agreed on my ability to use the download on 5 computers but they did not have the tools to get me a Mac download.
The customer agent agreed that the Premier Download purchased from Costco allows 5 Federal filings. I am allowed to install the windows exe downloaded for the given license code on 5 computers. This is clearly stated on the Desktop CD box as well. Logically assuming, I hope Costco is not expecting the same person to sit on his own computer and file for 5, but let his adult family members to do it themselves. Also, not everyone in the household cannot be assumed to have the same Operating System - some can choose Mac while others use Windows. This year, the online InstallTurboTax.com site is incorrectly mapping the license code to either Windows or Mac Operating System instead of allowing both options. It makes no sense that you allow the installation on 5 computers but all 5 have to be Windows or Mac machine but cannot be a mix of both. As an example, if I purchase a family subscription of Microsoft Office of 6 subscriptions - I can use that Office license on both Mac and Windows machines as long as it is a total of 6. It does not force me to use 6 Windows or 6 Mac machines. Similar to the Microsoft Office, the TurboTax license code should enforce and limit to only 5 installations, but should not limit to ONLY WINDOWS or ONLY MAC.
To be clear, a lot of the members including me did not have this issue last year. I can see both Mac and Windows download options in my Downloads list. It is reasonable to believe that a lot of the folks that do their own taxes using TurboTax are smart and computer savvy enough. It is the TurboTax rules that are getting dumber each year and coming up with weird restrictions that are either not stated upfront or are silly bugs that they refuse to acknowledge and fix. While the agent agreed with all my points, they could not help me out. Surprisingly, I did not get a survey asking me for feedback on the help [or lack of help] provided.
I hate to say this but TurboTax is slowly turning into Comcast/Xfinity monopoly that does not care about its own paying customers. [TurboTax - Prove me wrong on this one and I will happily eat my words].
To save my own sanity, I spent an extra $50 to buy an external CD/DVD drive that connects to Mac and simply do what the desktop version was intended to do.