do not see the optionto start a new return

[BJMACK1952]

do not see the optionto start a new return

[DoninGA]

Click on State on the left side of the online program screen.  

You would also have be requested to start a state tax return after you completed the Federal Review section of the progrm.

[DoninGA]

Since you did not specify State in your post, I assume you are referring to starting another online tax return.

The TurboTax online editions can only be used for one tax return per account and User ID.  You will need to create a new account with a new User ID for another tax return.  Click on Sign up at the top right of the following website to start a new account - https://turbotax.intuit.com/personal-taxes/online/file-your-own-taxes/