Thank you! This is really helpful. I just have one more clarifying question. When you say "When DC asks for 'income while residing out of state' subtract the DC amount from your total income and enter that amount" do you mean total income as gross income or what appears in Box 1? The reason I'm confused is because while I received two W-2s, only one of them has Boxes 1-14 filled out (the DC one). In other words, Box 1 is not split up between CA and DC. The only boxes that are different are Boxes 15-17 since those are state wages and they obviously do not add up to Box 1. Based on this, I'm not sure what total income you are referring to.
Additionally, for the question where I have to answer how much I earned living or working in CA, the total adjusted income seems to be the sum of my lone Box 1, my spouse's two Box 1 from is two separate W-2s from separate employers, and our HSA contributions. So I don't think Box 16 is applicable?
