Washington’s historic income tax is now law. But Republicans promise challenges

March 30, 2026 / 2:01 pm

caption: Gov. Bob Ferguson signs Senate Bill 6346, also known as the "millionaires tax," into law on Monday, March 30, 2026.

Gov. Bob Ferguson on Monday signed Washington’s historic income tax on the state’s highest earners. Republicans plan to challenge the new law in court and at the ballot box.

The measure would levy a 9.9% tax on all incomes over a million dollars beginning in 2029. It would raise roughly $3 billion in revenue from about 20,000 households, less than 1% of Washington’s population. That revenue would fund child care subsidies, tax breaks for low-income families, and sales tax breaks, while also supporting the state’s general fund.

Ferguson sounded confident that the law would survive courtroom tests or a vote of the people.

“There’s going to be a public conversation around this in the days and weeks and months ahead as there should be for something of this historic nature,” he said. “When Washingtonians hear the benefits that flow to working families, to businesses large and small, to kids in schools with those free meals, more child care services for thousands of Washington families, it’s going to make a huge huge difference.”

Washington state currently does not have an income tax, and instead relies on a mix of sales, property, and business taxes to support state services. Democrats like Ferguson point out that this system requires lower-earning people to pay a larger share of their income on taxes.

“Washington families whose income is in the bottom 20% pay a whopping 13.8% of their total income in state and local taxes, while the wealthiest pay a far smaller percentage of their income,” Ferguson said. “That’s not fair and that’s not right.”

Democrats say the new tax would stabilize the state’s general fund, which they say has been imperiled due to a rising budget deficit that necessitated cuts to early childhood education and child care programs this year.

Gwen Goodfellow, a caregiver and board member of SEIU 775, said she was excited about the passage of the tax. The tax would provide sales tax breaks for over-the-counter medications, personal hygiene products, and diapers.

“I’ve done the math, it would take me 18 years to earn the threshold income to even pay this tax, so having a fairer tax system is better for all of Washington,” Goodfellow said. “I’m telling my friends, when you look at your grocery cart, look at your shampoo, the over-the-counter medications, your diapers, and think about not paying sales tax on those things and how that will ease the burden in your household, it just means the average worker in our state can afford to keep working.”

The tax has garnered widespread opposition from Republicans in the Legislature. Rep. Jim Walsh (R-Aberdeen) said Republicans were concerned that a tax like this could eventually be made to apply to all income levels, not just the ultra-wealthy.

“The state constitution has language about taxes like this tax proposal and it says that they have to be uniform on all people and households and entities in Washington state, and the fact that the Governor’s rhetoric around this proposal is that it’s only applying to millionaires is not uniform,” Walsh said.

Tech executives across the state said its passage would cause large-scale flight of innovation and tech companies in the region. But not all of the state’s wealthy executives are opposed.

“For those saying us rich folks will leave if taxed, I can promise you, we won’t pack up en masse, and any who leave will be replaced,” said Brian Kirschner, a tech executive who works in artificial intelligence. “Washington is on the brink of creating a lot of wealth through AI, we are right to capture some of it and make sure everyone benefits through education, health care, and more tax fairness for small businesses and working families.”

Before the ink on Ferguson’s signature was even dry, opponents were already preparing to mount legal challenges.

Former Washington Attorney General Rob McKenna and the Citizen Action Defense Fund said Monday they would sue over the constitutionality of the tax.

Rep. Walsh has said more lawsuits would be coming from the state GOP.

Let’s Go Washington, a conservative committee backed by wealthy investor Brian Heywood, is leading another effort to repeal the tax.

The group announced Monday that they’re collecting signatures to file a referendum, a petition to the Secretary of State, to put a repeal of the law to voters.

But the law contains a “necessity clause” that bars referendums from being filed against it, something Republicans have said is unconstitutional. Democrats say enacting this tax is a budget emergency, and that it should go into effect as soon as possible. Let’s Go Washington says their filing of a referendum is a challenge to explore all options on how they can repeal the law, although they expect the Secretary of State to reject it.

Let’s Go Washington will also likely be gathering signatures to put a repeal of the tax to voters in November, in the form of a ballot initiative.

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Sarah Mizes-Tan
State Government Reporter

Sarah Mizes-Tan leads coverage of Washington state government for KUOW and KNKX and reports stories of people affected by officials’ decisions. Her work reaches audiences across Washington, Idaho, and Oregon through the Northwest News Network.
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