NJ resident working in CT.

Nonresidents of CT are subject to CT withholding but will get a credit on their resident state tax return for taxes paid to CT.  Refer to the CT Department of Revenue FAQ for nonresidents.

To help ensure that you create the correct state tax returns, review your personal information that you've entered in TurboTax, delete the state returns, and start over.  You shouldn't ‌be paying taxes on the same income in both CT and NJ. 

To delete your CT and NJ tax returns, follow the steps below:

1. Open TurboTax and select State from the menu and Continue
2. On Status of your state returns screen select delete next to NJ and CT and confirm.

Refer to the TurboTax article How do I delete my state return in TurboTax Online?

To review your answers in the Personal Info section:

1. Open TurboTax and select Personal Info
2. A Personal profile summary screen will pop up
3. Select Edit 
4. Scroll through the screens to ensure that you have the correct answers for your state of residence
5. Scroll down to Other State Income and select Edit
6. Check your answer for Did you make money in any other states? Answer Yes, and indicate that you made money in CT.

After you complete your federal tax return and you move to the State Taxes sections, both your nonresident CT and resident New Jersey state returns will be listed.  Prepare your nonresident tax return first. You will get a credit on your NJ tax return for the taxes that you paid to CT.

For additional information, refer to the TurboTax Help articles Do I have to file tax returns in more than one state?,  Why would I have to file a nonresident state return? and How do I file a nonresident state return?