If you owe tax due for your 2018 return it will be shown on line 22 of your Form 1040. And if you owe back taxes from an earlier year, and you are showing a 2018 refund on line 20a, the IRS will offset some or all of your 2018 refund to pay the back taxes owed.
Of course--you do understand you cannot be getting a refund and have tax due on the SAME tax return.
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.
https://turbotax.intuit.com/tax-tips/tax-payments/who-can-garnish-an-income-tax-refund/L7cPPzDyc
**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.**
