As far as I understand, if I am a resident of NY but make income in other state (CT), then I am supposed to fill out nonresident CT income tax as well as NY state income tax.
I thought that we were supposed to get the CT income tax amount credited to NY state income tax to avoid double taxation, however, when I look at my NY Tax Summary under Tax Tools, I don't see anything regarding CT tax amount.
Also, is New York Adjust Gross Income supposed to be equal to CT Adjust Gross Income even though I get 100% of my income in CT?
If you are a permanent resident of NY but you have earned income in CT, then you will need to file a CT nonresident state income tax return (for your CT source income only - your CT wages). You will also need to file an NY resident state tax return (for all income from all sources including CT wages). You will get a state income tax credit in NY for any CT state income taxes that you paid on your nonresident CT state income tax return.
You will want to work on your nonresident CT state income tax return first.
Some additional information about NY state income taxes:
NY taxes all the income reported when calculating NY state income taxes (whether resident, part-year resident or nonresident) but you will only be required to paid a portion of the total NY state income taxes calculated (your percentage of the total NY tax that relates to your NY source income only)
The way that the NY state income tax return works is that NY looks at all of your income from all sources and generates a total NY state income tax on all income. When NY is determining the actual NY state income taxes that you owe, NY multiples the total NY taxes on all income by the percentage of NY source income over all source income. For NY residents, all income from all sources will be taxed on your NY resident state income tax return.
So if all your income is from CT, then your total CT income and your NY income could be the same amount.
Just follow the TurboTax guide when working on your states (remembering to do your nonresident state return first) and TurboTax will do all the calculations and credits to your resident states return.
Here is additional information about filing in multiple states (select "see more answer" to view the entire attachment)