Connecticut State Department of Revenue Services

Walk-in services at all DRS branch office locations remain suspended. Email DRS at drs@po.state.ct.us. Email the Priority One Taxpayer Assistance Program: DRSPriorityOne_CollectionsAssist@po.state.ct.us. Please check our Frequently Asked Questions page.

Part-Year Residents

A part-year resident is anyone who changed his or her legal residence from or to Connecticut during the taxable year.  

Part-year residents of Connecticut must complete:

  • Form CT 1040NR/PY,
  • Worksheet CT-1040AW, and
  • Schedule CT-SI.

Visit our Individual Tax Forms Page for forms and instructions.

If you moved into or out of another state during the taxable year, you may also be required to file a part year return with the other state in which you were a resident during the taxable year. 

Contact the tax department in that state for further information. 

NOTE:  If you changed your legal residence to another state but continued to maintain a  permanent place of abode in Connecticut for the entire year and spent more than 183 days in Connecticut in the aggregate during the taxable year, you will be considered to be a resident for that year.

What Income Is Subject To Connecticut Tax?

The general instructions for Form CT-1040NR/PY include information about who should file this form as well as other helpful advice.

A part-year resident's total income during his or her period of residency and his or her Connecticut source income during his period of nonresidency are subject to Connecticut income tax. (Connecticut source income of a nonresident is defined in the instructions to Form CT-1040NR/PY.) A part-year resident is also subject to Special Accrual Rules. 

On the CT-1040AW, Part-Year Resident Income Allocation Worksheet, enter your income received or accrued while you were a CT resident in Column B.  Enter in Column D any income you received from a CT source after you changed your residence to another state.  It is the total of Column B and D that you must enter on Schedule CT-SI. The total from Line 30 of Schedule CT-SI must be entered on Line 6, Form CT-1040NR/PY.  That is your CT source income.

Special Accrual Rules

A part-year resident is also subject to Special Accrual Rules.  A part-year resident must recognize and report items of income, gain, loss or deduction on the accrual basis, regardless of the method of accounting normally used.  In general, an item of income is subject to special accrual if the right to receive the income is fixed and the amount to be paid is determinable with reasonable accuracy at the time residency status is changed.  More information on income subject to Special Accrual is found in the instruction booklet for Form CT-1040NR/PY.

Calculation Of Tax By Part-Year Residents

Connecticut law requires a part year resident to calculate his or her tax in the same way as a resident of Connecticut - on all income received or accrued for the entire year, regardless of where it was earned.  However, the part year resident will only owe the portion of the tax that is attributable to his or her Connecticut source income.  The part-year resident will prorate the tax that would be due on all of his or her income based upon the percentage of income from Connecticut sources.

For example, if the Connecticut income tax calculated on your entire income (as reported on Line 5 or Line 6 (whichever is greater) of Form CT-1040NR/PY) was $1,000, but you were a part-year resident and only 50% of your income was earned while you were a resident of Connecticut, your Connecticut taxable income would be 50% of $1,000, or $500.

This method of calculation allows the part-year resident to be taxed at the same rate as a resident, taking into account the same exemptions and tax credits available to a resident at the same income level, but only requires payment of the tax in relation to the percentage of total income derived from this state.  This method of taxation, also employed by New York and California, as well as other states, is intended to result in a fair collection of only the amount of tax due to Connecticut.

If Spouses Have Different Residency

If one spouse is a part-year resident and the other is a nonresident or a resident for the entire year, the spouse who is a part-year resident must file Form CT-1040NR/PY as a part-year resident using the filing status of married filing separately even if they file a joint federal income tax return.  (If the other spouse has a filing requirement, that spouse must file the nonresident or resident return (whichever is appropriate) as filing separately.) Likewise, if both spouses are part-year residents but they moved into or out of Connecticut on different dates, they must file as married filing separately, even if they file a joint federal income tax return.  In both instances, the spouses may not file as “married filing jointly" for Connecticut income tax purposes. 

For example, if you were a part year resident of Connecticut who is required to file a Connecticut return and your spouse was a nonresident of Connecticut with no Connecticut source income, you should file Form CT-1040NR/PY as "filing separately for Connecticut only" if you and your spouse file a joint federal income tax return.  If your spouse is a nonresident with Connecticut source income, he or she must also file Form CT-1040NR/PY as “filing separately.”  You are required to file a Connecticut income tax return if:

  • Your share of federal adjusted gross income exceeds $12,000, or
  • If your share is $12,000 or less but you had Connecticut income tax withheld from wages or made estimated payments of Connecticut income tax, or
  • You had a federal alternative minimum tax liability.

On Line 1 of Form CT-1040NR/PY you should include only your share of the federal adjusted gross income.  To determine your share of federal adjusted gross income, you should recompute your federal adjusted gross income by completing a pro-forma federal income tax return as if you were filing as married filing separately for federal income tax purposes. 

In filling out Worksheet CT-1040AW, include in Column A, only items of income that are included in your share of federal adjusted gross income reported on Line 1.  In Column B, enter income from Column A that was received or accrued during your residency period.  Enter the difference between the amounts in Columns A and B, in Column C.  In Column D, enter any part of Column C that was income from a Conn. source that you receive or accrued while you were a nonresident of Connecticut.

In calculating the tax, use the column for “filing separately”.

If You Worked in Another State While You Lived in Connecticut

If you worked in another state while you were a resident of Connecticut and you paid income tax to that state, complete Schedule 2 of Form CT-1040NR/PY to claim credit for the taxes paid to the other state. You may only claim credit for taxes paid to the other state on wages earned in that state during the time you were a resident of Connecticut.  You must attach a copy of the return filed with the other state in order to support your claim for credit.

Are Estimated Payments Required?

A part-year resident who will owe $1,000 or more in Connecticut income tax, after subtracting Connecticut income tax withheld during the taxable year and after taking into account any Pass-Through Entity Tax Credit and the credit for taxes paid to another jurisdiction on income earned in that jurisdiction, should make estimated income tax payments.  In general, four installments are due: April 15, June 15, September 15, and January 15.  Form CT-1040ES, Estimated Connecticut Income Tax Payment Coupons, is used for this purpose.  The worksheet explains the calculation of tax on Connecticut taxable income for residents, nonresidents, and part-year residents.