Other than a larger typeface and larger informational boxes the Form 1040-SR is the same as the Form 1040. The exact same Line Numbers and the same calculations on both forms. There is no difference between the two.
What TurboTax program are you using? The desktop CD/Download edition software installed on your personal computer or the online web-based editions where you created an online account with a User ID and Password?
If you are using the online editions, it sounds as if you are being asked to upgrade the edition you are using due to the tax data that you hare entered. Not which Federal Tax Return you are using, 1040-SR or 1040.
