There are a few things that can bump you up to the Deluxe or Premier version, like having an HSA at work, or certain IRA contributions.
If you use Turbotax Online, start in the Free version and let the program tell you if you need to upgrade. If you want to use Turbotax installed on your own Mac or PC, the best value is to buy the Deluxe Federal+1 Free State version from a reliable third party retailer like Amazon, Target, Staples, Best Buy, and so on. The Desktop Deluxe version includes all the forms that might be needed even if you have a special situation.
