You're going to look at your return:
Go to My Account.
Go to Tools.
Go to View Tax Summary.
Go to Preview my 1040.
Go to line 71 on the second page of Form 1040.
If there's an amount there, then it'll be added to your Total Payments, just like Federal Withholding, and come back to you either in the form of a refund, or a reduction of your taxes due.
