I am pretty sure I have this correct, but am posting to verify my understanding and also to share. This relates to NYC school tax credit (rate reduction amount) - line 69A. This relates to a couple each earning ~$300K each (it's not me!). If taxes are done married filing jointly, they exceed the $500K threshold and the credit it $0. If they file married filing separately, the combined credit is over $1200. Does that sound about right? TurboTax did the calculations -- I did not need to provide anything special other than the interview question. I actually did the taxes both jointly and separately and compared the two and identified the difference.
