Initiative 645, the Repeal Tax on Household Income Over $1 Million and Prohibit State and Local Taxes on Income Initiative, is a direct initiated state statute that will appear on the November 3, 2026, ballot in the U.S. state of Washington. If approved by voters, the initiative would repeal the millionaires tax, a 9.9 percent tax on household income exceeding $1 million per year that was approved by the Washington state legislature in March 2026.
Background
Washington's millionaires tax imposes a flat 9.9% tax on taxable income exceeding $1 million per household, with married couple or domestic partnerships sharing a single $1 million standard deduction. The tax starts from federal adjusted gross income and is adjusted for various factors, including capital gains and charitable deductions. The $1 million standard deduction is indexed for inflation beginning in 2030.
The tax applies to Washington residents, part-year residents, and nonresidents who derive Washington-source income, including wages for services performed in Washington, income from a Washington business or pass-through entity, and rents or gains from Washington real or tangible personal property. Before the millionaires tax was passed, proponents estimated the tax would generate $3.5 billion or more per year once collections begin in 2029. The tax directs the revenue to public defense, the state's Working Families Tax Credit, small business tax relief, and sales tax exemptions.
Impact If the initiative is approved by voters, the millionaires tax would be repealed and future taxes on income would be prohibited. The initiative would also define income as "any gain or benefit measured in money derived from an individual's capital, labor, property, or other source."
Endorsements
Polling Poll sourceDate(s) administeredSample sizeMargin of errorYesNoUndecidedDMH ResearchSeptember 14–21, 2026800 (A)± 3.5%35%57%8%40%44%16%GBAO Strategies (D)June 7–11, 20261000 (LV)± 3.1%38%57%5%
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