I will second having done this myself. There was a disagreement between how the tax credit for Obamacare/ACA was being taken by my mother versus I because I was

I will second having done this myself. There was a disagreement between how the tax credit for Obamacare/ACA was being taken by my mother versus I because I was transferring from being covered under her insurance to being covered under my own. The IRS said I owed more than I did because the tax credit couldn't be used twice, while my mother and I disagreed we bickered back and forth with the IRS for about a year but they gave up and let us count it.