Moving From Washington to Arizona: What Happens to Your Taxes in Retirement?

On ordinary income, Washington is the cheaper state and Arizona is the more expensive one. Washington has no personal income tax, so pension payments, IRA and 401(k) withdrawals, annuity income, interest, and dividends are untaxed at the state level. Arizona applies a flat 2.5% to the same income, with Social Security fully exempt in both states. As in any zero-tax-to-low-tax move, that is a real recurring cost, though 2.5% is modest by national standards.

Washington's capital gains excise tax runs the other way. It applies to long-term gains on stocks, bonds, business interests, and similar assets above an inflation-indexed annual threshold in the high $200,000s, at 7%, with an additional increment on very large gains that pushes the top rate near 10%. Two exclusions matter enormously for retirees and are widely misunderstood: real estate sales are entirely exempt, and gains realized inside retirement accounts are exempt, so ordinary IRA and 401(k) activity never triggers it. What it does hit is the retiree with a large taxable brokerage account who sells a concentrated position, or the owner who sells a business.

Arizona has no equivalent tax. It treats a long-term capital gain as ordinary income subject to the flat 2.5%, then applies a 25% subtraction to long-term gains, producing an effective state rate of roughly 1.875%. Against Washington's 7% or more on gains over the threshold, that is a large gap. A retiree sitting on a highly appreciated position they intend to unwind should think carefully about which side of the move that sale lands on.

The estate tax is the piece that most often dominates the whole analysis for higher-net-worth households, and it is easy to overlook because it feels distant. Washington is one of a small number of states with its own estate tax, entirely separate from the federal one, with an exclusion of roughly $3 million and graduated rates above that. Because the federal exclusion is many times larger, a Washington couple can be nowhere near owing federal estate tax while still facing a substantial Washington bill. Arizona has no estate tax and no inheritance tax. For an estate meaningfully above the Washington threshold, establishing Arizona domicile can be worth more than every income tax consideration in this article combined.

Those three facts produce a sequencing rule that genuinely splits. Ordinary income you control, most importantly Roth conversions, is cheaper recognized while you are still a Washington resident, where the state rate is zero rather than 2.5%. Large long-term capital gains above Washington's threshold are cheaper recognized after you have established Arizona domicile, where the effective rate is roughly 1.875% rather than 7% or more. Two different levers, two different sides of the same move.

As with any change of domicile, the benefit depends on the move being real rather than nominal. Establishing Arizona domicile means the ordinary evidence: driver's license, voter registration, where your primary home is, where your physicians and advisors are, and where you actually spend your days. Washington's estate tax in particular reaches the estates of people who were domiciled there at death, so a half-completed move that leaves domicile ambiguous can produce the worst of both outcomes.

Rates and thresholds in this area move. Washington's capital gains threshold is indexed annually, and both its estate tax exclusion and its rate schedule have been changed by the legislature more than once in recent years, including changes taking effect partway through 2026. Check the current figures with the Washington Department of Revenue before acting rather than relying on any secondary summary, including this one.

If your estate is anywhere near or above roughly $3 million, start the analysis with the estate tax rather than the income tax. Arizona having no estate tax is very likely the largest single number in this decision, and it is the one most often left out because it feels far off.

If you hold concentrated appreciated positions in a taxable account, map out when you intend to sell before you decide when to move. Gains above Washington's threshold are taxed at 7% or more there and roughly 1.875% in Arizona, so a sale on the wrong side of the move can be an expensive accident.

Split your planning calendar. Roth conversions and other ordinary income you can control belong on the Washington side, where the state rate is zero. Large capital gains belong on the Arizona side. Very few relocations pull in two directions like this, and the households that plan for it capture materially more than the ones that treat the move as a single event.

• Leaving the Washington estate tax out of the analysis entirely because the federal exclusion is so much larger. Washington's threshold is a small fraction of the federal one, and plenty of households owe Washington estate tax while owing nothing federally.
• Assuming Washington's capital gains tax applies to retirement account withdrawals or to a home sale. Neither is subject to it, which means some retirees overestimate what they are escaping while others miss the one case, a large taxable brokerage sale, where it genuinely bites.
• Selling a large appreciated position while still a Washington resident when the sale could have waited until Arizona domicile was established, paying 7% or more instead of roughly 1.875%.
• Doing the reverse with a Roth conversion, waiting until after the move and paying Arizona's 2.5% on income that would have been state tax free as a Washington resident.
• Making a partial move that leaves domicile genuinely ambiguous. Washington's estate tax follows domicile at death, so an unfinished relocation can leave you paying Arizona income tax while still exposed to the Washington estate tax.