If you haven't already mailed your 2016 paper return, you can switch to the e-filing method (through October 17, 2017). Some states now require e-filing their returns, and federal and state returns must be e-filed together.
On the other hand, if you already mailed your return, don't e-file. This can cause problems with the government, including refund delays.
If you wish to change how you'll file your taxes in TurboTax, follow the steps below for either the TurboTax Online or TurboTax CD/Download version.