Yes, you can upgrade to the CPA/EA review at any time before filing. To upgrade follow the steps below:
1. Once signed into your online account and in your 2017 return, click on the Help icon on the top right.
2. Select Contact Us on the bottom of the help window.
3. Type in Add Expert Services and select Continue.
4. Select the Speak with a live CPA or EA icon towards the bottom and on the next window select Get Expert Services.
Soon there will be an "Upgrade" option to click on that will take you directly to all upgrade options. In the mean time, the steps above can be used to add Expert Services with final review.