Moving from one U.S. state to another can turn a normally simple tax return into two or more state filings.
For the year of the move, the states involved generally look at two things: how long the taxpayer was a resident and where income was earned while a nonresident. A part-year resident may owe tax on worldwide income during the period of residency, plus income sourced to the state during the nonresident period.
The exact calculation varies by state. The move date matters, but it is not always the only thing that determines residency.
How part-year state tax is calculated
There is no single nationwide formula for part-year state returns.
California, for example, taxes all worldwide income received while someone is a California resident. After the person becomes a nonresident, California generally continues to tax income from California sources. That can include compensation for services physically performed in California, California rental income and certain business income.
New York uses a different allocation system for part-year residents. Form IT-203 is used by nonresidents and part-year residents, with income allocated between federal income, New York-source income and the period of New York residency.
The important point is that moving on a particular date does not automatically mean every dollar earned before and after the move is simply divided by months. Wages, investment income, business income and other types of income can have different state-source rules.
The move date is not always the end of the story
One of the biggest mistakes is assuming that changing a driver’s license, signing a new lease or moving household belongings automatically ends state residency.
States can have their own tests for determining whether a person has actually changed domicile or remains a resident.
New York is particularly important for people who move out of the state but keep a home there. A person can be treated as a New York resident even when New York is no longer their domicile if they maintain a permanent place of abode in New York for substantially all of the tax year and spend at least 184 days in the state. Any part of a day counts as a day for this test.
That means a move that looks complete from a federal-tax perspective can still create a New York state residency issue.
California also looks at domicile and the facts surrounding a move. Its rules distinguish between residents and nonresidents, and California can continue taxing California-source income after someone becomes a nonresident. California also has specific rules and presumptions that can affect residency determinations.
What happens when moving to a state with no individual income tax?
For 2026, eight states do not impose an individual income tax: Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas and Wyoming. Washington does not impose a broad individual income tax on wages and salaries, but it has separate taxes that can apply to certain capital gains and, beginning in 2026, certain very high levels of Washington taxable income.
So a move from California to Florida, for example, does not erase the California tax obligation for the part of the year spent living in California. California can still tax worldwide income received during the California-resident period and California-source income afterward.
Washington also deserves special attention for investors. Its capital gains tax changed in 2025, with a 7% rate applying to the first $1 million of taxable Washington capital gains and a higher 9.9% rate applying to the portion above $1 million.
The old idea that Washington simply has “no income tax” is therefore incomplete for someone with substantial investment gains.
What if the move involved New York City?
Moving into or out of New York City during the year can create a second layer of state and local filing requirements.
A person who was a New York State resident for only part of the year generally uses Form IT-203. If that person was also a New York City resident for part of the year, Form IT-360.1 is used to calculate the part-year New York City resident tax.
New York City calculations can also involve prorated credits, exemptions and other amounts based on the period of city residency. The city’s part-year instructions, for example, require the taxpayer to determine the applicable resident period and use the corresponding proration rules.
Yonkers has its own rules as well, so a move involving New York City or Yonkers should not be treated as a state-only filing issue.
What happens if the job is in another state?
Remote work can make a state move much more complicated.
A taxpayer may live in one state while working for an employer based in another. The tax result depends on the states involved and, importantly, where the services are considered to have been performed under the applicable state rules.
New York has a particularly important rule for employees whose assigned or primary office is in New York. Under its convenience-of-the-employer rules, certain days worked from a home office outside New York can still be treated as New York workdays unless the out-of-state work is attributable to the employer’s necessity or the home office qualifies as a bona fide employer office under the state’s rules.
That can create an unexpected New York tax bill for someone who physically works from another state.
Other states have their own sourcing and telecommuting rules. There is also no universal filing threshold for nonresidents. As of 2026, some states can require a nonresident return after even a limited amount of work performed in the state, while others provide thresholds based on days worked or income earned.
Can the same income be taxed by two states?
Potentially, but states often provide a credit for income tax paid to another state.
The exact credit depends on the states involved and the type of income. It is generally designed to reduce double taxation when the same income is taxed by both the taxpayer’s resident state and another state where the income was sourced.
But the credit is not a universal escape hatch. Limitations can apply, and special sourcing rules can produce situations where the full amount of tax paid to another state is not completely offset.
This is one reason interstate moves involving remote employment, business income or investment income can require more than simply entering the same federal numbers on two state returns.
What about F-1 and J-1 students?
Federal immigration and tax status does not automatically determine state tax residency.
For federal tax purposes, certain F-1 and J-1 students can exclude days of U.S. presence when applying the substantial presence test. F-1 students generally receive the student exemption for up to five calendar years, subject to the applicable requirements and exceptions. J-1 rules depend on whether the person is a student or a teacher/trainee, with different time limits. See also: A Court Blocked the F-1 “End Date” Rule One Day Before It Took Effect. What Applies Now?.
State residency is a separate question.
A student who is a federal nonresident alien can therefore still need to examine the residency rules of the state where they live, study or earn income. Conversely, federal residency does not automatically make someone a resident of a particular state.
This distinction is especially important for international students who move between states during the academic year.
What documents should be kept after a move?
A clean paper trail can make the state filing much easier.
Keep records showing:
- The date the old home was left
- The date the new home was established
- Lease or purchase documents for both homes
- Driver’s license and vehicle registration changes
- Utility records
- Employer work-location records
- Days physically spent in each state
- Income earned before and after the move
- Investment sales and other potentially state-sourced income
- State tax withheld from each paycheck
For remote workers, keeping a calendar of where work was physically performed can be particularly important. State sourcing rules can depend on workdays rather than simply the employer’s headquarters or the employee’s mailing address.
The part-year tax rules at a glance
| Situation | What to check |
|---|---|
| Moved between two states with income taxes | Part-year residency and state-source income in both states |
| California move | Worldwide income during California residency plus California-source income while nonresident |
| New York move | Form IT-203 and New York residency/domicile rules |
| Kept a New York home after moving | 184-day statutory residency test and permanent place of abode rules |
| Moved into or out of New York City | Possible Form IT-360.1 filing and NYC tax proration |
| Moved to a state without broad wage income tax | Tax may still be owed to the former state for the resident period |
| Moved to Washington | Separate Washington capital gains rules can apply |
| Remote employee | Check where services are sourced and whether telecommuting rules apply |
| F-1/J-1 student | Federal tax residency and state tax residency are separate questions |
A mid-year move does not automatically mean splitting the year’s income evenly between two states. The actual tax result depends on residency dates, domicile, where income was earned, the type of income and each state’s sourcing rules.
Before filing, organize the move dates, physical presence records, income by period and state withholding. For complicated moves, especially those involving New York, California, remote work or substantial investment income, the state-specific rules can matter more than the federal return itself.
Sources: California Franchise Tax Board, New York State Department of Taxation and Finance, Washington State Department of Revenue, IRS, and Tax Foundation.
