Moved from District of Columbia to Connecticut Mid-Year: Which State Tax Returns Do You File?
Answer
Both states want a return, but neither taxes the whole year. Moving from District of Columbia to Connecticut splits the tax year at the date your residency changed: a District of Columbia part-year return covers everything before it, a Connecticut part-year return everything after. Income is assigned by when it was received.
Last verified
A mid-year move splits the tax year in two, and each state taxes its own half. That is a residency question, so the machinery that governs commuters — reciprocity agreements, convenience rules, nonresident withholding — is beside the point here.
What you file
- 1Part-year return · District of ColumbiaForm D-40 (part-year resident)
File a District of Columbia part-year return covering the months you lived in District of Columbia. A part-year resident of District of Columbia reports the income received while a District of Columbia resident, plus any District of Columbia-source income received during the rest of the year, and prorates the deductions and credits to the residency period.
- 2Part-year return · ConnecticutForm CT-1040NR/PY
File a Connecticut part-year return covering the months you lived in Connecticut. A part-year resident of Connecticut reports the income received while a Connecticut resident, plus any Connecticut-source income received during the rest of the year, and prorates the deductions and credits to the residency period.
The two states, side by side
| District of Columbia | Connecticut | |
|---|---|---|
| Taxes wages | Yes — graduated | Yes — graduated |
| Reciprocity partners | 2 (Form D-4A) | None |
| Convenience rule | No | Only against convenience-rule states |
| Nonresident return | None — nonresidents exempt | Form CT-1040NR/PY |
| Part-year return | Form D-40 (part-year resident) | Form CT-1040NR/PY |
| Credit for other-state tax | Schedule U (Form D-40) | Schedule 2 (Form CT-1040) |
| Nonresident safe harbour | Not applicable | None published |
| Local income tax | No | No |
| Revenue department | District of Columbia Office of Tax and Revenue | Connecticut Department of Revenue Services |
| Last verified |
The other direction
Reversing the commute does not always reverse the answer. Living in Connecticut and working in District of Columbia gives:Two part-year returns.
Same two states, different situation
The withholding answer turns on how you are paid and where the work happens, not only on which two states are involved.
- W-2 commuter: District of Columbia → ConnecticutBoth states — credit offsets the double tax
- Remote worker: District of Columbia → ConnecticutHome state only
- 1099 contractor: District of Columbia → ConnecticutHome state, plus the client state if you work there
Other District of Columbia pairs
Questions people actually ask
I moved from District of Columbia to Connecticut mid-year. Do I have to file in both states?
Both states want a return, but neither taxes the whole year. Moving from District of Columbia to Connecticut splits the tax year at the date your residency changed: a District of Columbia part-year return covers everything before it, a Connecticut part-year return everything after. Income is assigned by when it was received.
How do I split my income between District of Columbia and Connecticut?
By when you received it, measured against the date your domicile actually changed. Income received while you were a District of Columbia resident belongs on the District of Columbia return and income received afterwards on the Connecticut return, with each state prorating your deductions, exemptions and credits to its own part of the year. Keep evidence of the move date — a lease, a closing statement, a licence issue date.
How current is this?
The District of Columbia and Connecticut rules on this page were last checked against District of Columbia Office of Tax and Revenue and Connecticut Department of Revenue Services on 2026-08-07. We re-check the full grid every December after state legislative sessions close, and re-check the convenience-of-the-employer states quarterly because that is where the rules move fastest.
Sources
Every fact above comes from the revenue department that publishes the rule. We do not cite secondary summaries, and we do not restate a figure we could not find at source.
- District of Columbia Office of Tax and Revenue — individual income taxaccessed 2026-08-07
- Connecticut Department of Revenue Services — individual income taxaccessed 2026-08-07