Residency rules, sticky taxes, and first-year steps (2026)
2026.1 Edition · Revised 2026-07-25 · DomusDay Research
The move changes the rate; the record decides whether it sticks. Colorado keeps taxing until domicile actually changes — domicile — the place a person considers their home; the permanent place of abode to which they intend to return whenever away, with no fixed day threshold to hide behind. Below: what follows leavers, and the Arizona steps that build the record.
Arizona taxes all income at a flat 2.5% — no brackets — and subtracts 25% of net long-term capital gains on assets acquired after 2011, putting the effective long-term rate under 1.9%.
Source ↗More than nine months in the state during a taxable year creates a rebuttable presumption of Arizona residency. For arrivals it works in your favor: the presumption and dated records anchor the part-year split.
Source ↗Arizona's homestead exemption — a $400,000 base, inflation-adjusted annually — attaches to the primary residence with no filing or recording required, unlike the declaration states.
Source ↗Arizona is the easy half. Colorado decides whether the move counts, and it decides on evidence — the two tests below stay live until the record closes them out.
The full rules, the audit program, and every source: the complete Leaving Colorado guide →
Top-bracket rates differ by 1.9%: Colorado at 4.4%, Arizona at 2.5% — an illustration at the top marginal rate, not an effective-rate calculation.
The first weeks in Arizona matter more than they look: each step below produces a dated document, and dated documents are what answer a Colorado examiner years later. Do them early and the record starts on your side of the timeline.
Arizona treats you as a resident for licensing once any trigger applies — seven months' presence in a calendar year, Arizona employment, voter registration, or children enrolled without nonresident tuition — and a license and registration follow.
Source ↗Vehicles are registered on becoming an Arizona resident, with Arizona liability insurance required; emissions testing applies in the Phoenix and Tucson areas.
Source ↗Voter registration requires Arizona and county residency; registration closes 29 days before an election and is available online through the MVD system.
Source ↗The Department of Revenue's residency procedure weighs vehicle registration, voter registration, property ownership, and a consistent permanent address — the same records the steps above generate.
Source ↗Arizona's homestead exemption — a $400,000 base, inflation-adjusted annually since 2024 — attaches to the primary residence automatically, with no filing required.
Source ↗Every vehicle operated on Arizona roads must carry Arizona liability insurance.
Source ↗Arizona is a community property state: property acquired by either spouse during the marriage is community property, with gift and inheritance exceptions — relevant to title, basis, and estate planning on arrival.
Source ↗The arrival year is filed on Form 140PY, the part-year resident return, splitting income at the residency change date.
Source ↗Everything Arizona asks of a new resident, on its own plate: the Moving to Arizona guide →
Every rule on this page traces to a statute, regulation, or agency publication, listed in full on each state's own plate.
More than six months of the tax year, in aggregate, while maintaining a permanent place of abode in Colorado. The rule is a prong of the resident definition itself, and Colorado states it in months — no 183-day count is published. An abode can be a house, condominium, apartment, room in a house, or mobile home.
Form DR 0104PN — the Part-Year Resident/Nonresident Tax Calculation Schedule — filed with the DR 0104. Tax is computed as though full-year, then apportioned by modified Colorado AGI over modified federal AGI, so it falls only on income received in Colorado or from Colorado sources.
2026.1 Edition · Revised 2026-07-25 · DomusDay Research