If you live in Massachusetts, but work in Maine, you pay taxes to both states. This question is asking how much of your income was earned in Maine, and how much tax did you pay to Maine on that income. If you prepared the Maine nonresident return first in TurboTax, this information usually transfers over automatically. If not, you will need to add up the amount of income that was earned in Maine (if your only job was in Maine, then you report all of your income), and then how much tax you paid. The amount of tax you paid is the amount of Maine tax withheld, subtracting out any refund, or adding up additional tax due to Maine. Massachusetts will give a credit for your MA return for up to the amount of tax you had to pay on your Maine return, or the amount that Massachusetts taxes the same income.
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