You're referring to TurboTax Live or Expert Services, correct? Yes, you can upgrade to either of these services once you've begun your return in one of the other editions. See the instructions below from a TurboTax FAQ.
https://ttlc.intuit.com/replies/6419943
*** I am NOT a tax expert. I am a seasoned TurboTax user, and volunteer to provide assistance to TT users. Nothing I post is to be considered TAX ADVICE; I bear no legal liability for responses.***
