Please see the following link for tax situations covered in TurboTax Free Edition.
If you don't qualify for TurboTax Free Edition, you may qualify for TurboTax Free File Program.
Here is more information on TurboTax Free File Program.
You can follow the instructions in the following FAQ to switch to the Free File Program.
If you do not qualify for either of the free products, then you would need to upgrade your account.