Enter it on your 2019 return as a payment to get credit for it.
Make sure you enter it on your return. It will show up on 1040 schedule 3 line 8 which goes to 1040 line 18d. It will either add to your refund or reduce your tax.
If it didn't transfer over from last year then enter a refund from last year that you applied to this year here. BUT first make sure it's not already there. You don't want to apply it twice.
Federal on left
Deductions and Credits at top
Then scroll way down to Estimates and Other Taxes Paid
Other Income Taxes - Click the Start or Revisit
Next page scroll down to 2018 Refund Applied to 2019
Click Start or Update by the tax you applied
To enter, change or delete a refund from the prior year applied to this years taxes (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 Other Income Taxes, click on the start or update button
On the next screen select the options under 2018 Refund Applied to 2019
Or enter refund applied to this year in the Search box located in the upper right of the program screen. Click on Jump to refund applied to this year
The prior year refund amount applied is shown on Schedule 3 Line 8 and on Form 1040 Line 18d as a tax payment and will be included with your federal tax refund on Line 20.