@SamPull It is not taxable and you aren't paying it back. Your 2021 return starts out by assuming you didn't get any Stimulus payments so it gives you credit for the full amount and your refund was too high. Then near the end you enter how much you actually got so it only gives you the difference if any. So you don't get it again.
Look at your return. The Stimulus payments do not show up anywhere as taxable income so you are not being taxed on it. And they are not being subtracted anywhere on your return either.
