You might have some taxes withheld from W-2's 1099R's 1099Misc.
Or a refund from last year applied to 2018 taxes.
Go and check the estimated tax payments and see what is entered.
Estimated Taxes Paid
To EDIT estimated taxes paid (Federal, State, Local)
• Click on Federal Taxes (Personal using Home and Business)
• Click on Deductions and Credits
• Click on I'll choose what I work on (if shown)
• Scroll down to Estimates and Other Taxes Paid
• On Estimates, click on the start or update button
