Tax consequences of changing state residency?
It also depends on where you work. If you move your home and your job then the date you establish residency in the new state is the key date. All income before that date is considered income for state 1, and all income on or after that date is income for state 2.  If there is a big  difference in income you will want to clearly establish residency because it impacts your wallet. If they had the same rates moving wouldn't impact your wallet, but it would impact each state. So make sure when going from high tax state to low tax state that you register your vehicles, register to vote, get a new drivers license... It becomes more complex if you move your home but not your job. In that case where you work might be the deciding factor. Same states have agreed that where you live is the deciding factor; in other cases it is not. For Virginia, Maryland, and DC you pay based on where you live if the two states involved are DC, MD, VA. But if you Live in Delaware and work in Virginia Virginia wants a cut of your income tax.  So before you move you need to research reciprocity for the two states. From Massachusetts information for Nonresident and Part-Year Resident Income, Exemptions, Deductions and Credits Massachusetts gross income includes items of income derived from   sources within Massachusetts. This includes income: a few questions later: Massachusetts residents and part-year residents are allowed a credit   for taxes due to any other jurisdiction. The credit is available only   on income reported and taxed on a Massachusetts return. Nonresidents   may not claim the taxes paid to other jurisdiction credit on their   Massachusetts Form 1-NR/PY. The credit is allowed for income taxes paid to: The credit is not allowed for: taxes paid to the U.S. government or a   foreign country other than Canada; city or local tax; and interest and   penalty paid to another jurisdiction. The computation is based on comparing the Massachusetts income tax on   income reported to the other jurisdiction to the actual tax paid to   the other jurisdiction; the credit is limited to the smaller of these   two numbers. The other jurisdiction credit is a line item on the tax form but you   must calculate it on the worksheet in the instruction booklet and also   enter the credit information on the Schedule OJC. So if you move your house to New Hampshire, but continue to work in Massachusetts you will owe income tax to Massachusetts  for that income even after you move and establish residency in New Hampshire.