Hi!
Former part year DC resident here.
TurboTax asks when completing your DC state taxes:
"Subtraction From Federal Income, Part-year --
Enter any income received while residing outside DC. If none, enter zero."
Thanks to ERnieS0's comment, I interpreted that to mean that TurboTax by default used my ENTIRE federal income (box 1 on my W2(s)) to calculate my part year DC taxes. To correct this, they offer the prompt above to calculate how much you earned while residing in DC.
To get the value I entered in that box, I subtracted from my total federal income (W2 box 1) what I earned in the months I lived in DC. So the box should just contain what income you earned while living outside of DC (AKA the remaining part year). For the original post that would be what they made in their new job out of state.
This drastically reduced my taxes owed (as expected because I really surprised to receive an estimate that I owed thousands from residing in DC for just a few months when I normally have very simple taxes).
