Yes, if you have not already mailed your tax return, you can change from mailing your Tax Returns to E-Filing your Tax Returns by following these steps:

• Login to your TurboTax Account 
• Scroll down to the bottom of your page and click on the blue box "Add a State" (You are not actually adding a state but this gets you to the correct menu)
• Click "File" from the left side of your screen
• Click "Start" next to Step 3 
• Click "I'd Like To Change Filing Methods"
• Choose "E-File" then click "Save"
• Click "Continue"
• From here you can walk through the steps to E-File your return(s)
• Finally, you will come to the screen with the Transmit Returns Now button. This will electronically file your selected returns.

Note: If you have already mailed your Tax Returns, DO NOT E-File them as this will just cause confusion with the IRS.