According to the Connecticut instructions:
A Connecticut Resident is an individual that is domiciled in Connecticut for the entire tax year. If you maintained a permanent place of abode in Connecticut and spent more than 183 days in the state, you are also considered to be a resident.
- If you are a resident, you may be treated as a Nonresident even if your domicile was Connecticut if you meet certain requirements. Please refer to the Connecticut Instructions for the conditions as outlined for individuals that fall into Group A or Group B.
A Connecticut Nonresident is an individual that is neither a resident or part-year resident during the year.
A Connecticut Part-Year Resident is an individual that moved into or out of Connecticut during the tax year. Part-Year residents may not elect to be treated as residents.
If ones spouse is a resident and the other is not, file Married Filing Separate returns. If you elect to file a Married Filing Joint return, your federal return must be Married Filing Joint and your income will be taxed as if both spouses are Connecticut residents.
- To file separate returns within your account, you can file the federal return and wait for the return to be accepted. Then, change the filing status for the primary taxpayer and file a separate return for the first spouse. The second spouse will need to create a new account and file the separate state return in that account (if required to file).
For more information: