NOTE: I realize this is an old thread that transferred in from the old AnswerXChange forum, but since some info is available, I'll go ahead and mention it here since other users may find this thread while searching for "Full Service."
TurboTax will be offering a new product "Full Service by TurboTax Live". With the new Full Service the CPA/EA tax expert will prepare your return from info and documents you provide, let you review it, then will sign and efile it for you.
I don't know if it's available already for 2018 returns or not, but I have asked. There are already some published FAQs on it, but I don't know the details yet or the pricing.
FAQ: What is Full Service by TurboTax Live?
TurboTax also has a less-inclusive product TurboTax Live, where you prepare the return but have on-demand access to a live CPA/EA tax expert during return preparation, so you can ask questions. And the expert will review the return prior to you filing it.
FAQ: What is TurboTax Live?