If you still owe back taxes, then your 2018 refund will be used to pay those taxes, even if you are on a payment plan. if there is anything left after the whole tax debt it paid you will receive the remaining refund.
To see back taxes owed
https://www.irs.gov/uac/view-your-tax-account
NOTE: You can contact the IRS Treasury Offset Program Call Center at 1-800-304-3107 to ask if they have an offset for you on file. TurboTax would not have that information.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
