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Moved from Illinois to Massachusetts Mid-Year: Which State Tax Returns Do You File?

Two part-year returnsBoth states claim the income

Answer

Illinois for the first part of the year, Massachusetts for the rest. Each state's part-year return reports the income received during that state's residency period and prorates the standard deduction, exemptions and credits accordingly. Keep evidence of the date you actually changed domicile.

Last verified

Part-year returns are designed so that neither state taxes the whole year. The risk is not double taxation by default; it is misassigning income received near the move date, and losing the proration on deductions and credits.

What you file

  1. 1Part-year return · IllinoisForm IL-1040 with Schedule NR

    File a Illinois part-year return covering the months you lived in Illinois. A part-year resident of Illinois reports the income received while a Illinois resident, plus any Illinois-source income received during the rest of the year, and prorates the deductions and credits to the residency period.

  2. 2Part-year return · MassachusettsForm 1-NR/PY

    File a Massachusetts part-year return covering the months you lived in Massachusetts. A part-year resident of Massachusetts reports the income received while a Massachusetts resident, plus any Massachusetts-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

 IllinoisMassachusetts
Taxes wagesYes — flatYes — flat
Reciprocity partners4 (Form IL-W-5-NR)None
Convenience ruleNoNo
Nonresident returnForm IL-1040 with Schedule NRForm 1-NR/PY
Part-year returnForm IL-1040 with Schedule NRForm 1-NR/PY
Credit for other-state taxSchedule CRSchedule OJC
Nonresident safe harbour30 daysNone published
Local income taxNoNo
Revenue departmentIllinois Department of RevenueMassachusetts Department of Revenue
Last verified

The other direction

Reversing the commute does not always reverse the answer. Living in Massachusetts and working in Illinois gives:Two part-year returns.

Massachusetts to Illinois →

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.

Other Illinois pairs

Questions people actually ask

I moved from Illinois to Massachusetts mid-year. Do I have to file in both states?

Illinois for the first part of the year, Massachusetts for the rest. Each state's part-year return reports the income received during that state's residency period and prorates the standard deduction, exemptions and credits accordingly. Keep evidence of the date you actually changed domicile.

How do I split my income between Illinois and Massachusetts?

By when you received it, measured against the date your domicile actually changed. Income received while you were a Illinois resident belongs on the Illinois return and income received afterwards on the Massachusetts 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 Illinois and Massachusetts rules on this page were last checked against Illinois Department of Revenue and Massachusetts Department of Revenue 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.