Apply one-time tax to billionaires to fund healthcare and education
Proposition 40 would require the estimated 200 Californians whose net worth exceeded $1 billion at the start of this year to pay a one-time 5% tax. Service Employees International Union-United Healthcare Workers West, the group that put the measure on the ballot, projects that it would raise roughly $100 billion over five years. That money would be earmarked primarily for healthcare, with some reserved for food assistance and education. If propositions 41 or 42 earn more votes than Proposition 40, this measure would be nullified.
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Summary
Support
Supporters argue that the people who would pay the tax are the ones who benefited the most financially from recent federal tax reforms. Congress also cut tens of billions from Medicaid, known as Medi-Cal in California, which provides health insurance to low-income people. SEIU-UHW argues those cuts will cause hospitals and clinics to close, costing thousands of jobs and worsening access for all patients.
Oppose
Opponents include Silicon Valley entrepreneurs, business interests, and some health and labor organizations. They say the proposal will backfire, causing billionaires to leave California and decreasing tax revenue in the long run. Health groups say they weren’t consulted in designing the measure and that it does not solve the long-term fiscal challenges of funding healthcare. The same groups backed propositions 41 and 42, competing measures that would place limits on new special taxes.
Endorsements
Support
Service Employees International Union-United Healthcare Workers West
Vermont Sen. Bernie Sanders
Teamsters California
AFSCME California
California Democratic Party
Campaign finance
Proposition committees raise money to support or oppose propositions. Outside groups can also raise and spend money independently to influence outcomes.
Proposition committees
Outside spending
Difference to other side
Proposition committees
These committees are primarily formed to campaign for or against a proposition. They must identify donors who give $100 or more. There are no limits on how much donors can give. Below, we exclude donors whose contributions total less than $100.
Outside spending
Separate from proposition committees, outside groups can pay for ads, mailers and other efforts to influence voters. They can’t coordinate that spending with proposition committees. There is no limit on how much they can spend.
Ballot text
IMPOSES ONE-TIME TAX ON CERTAIN TAXPAYERS. INITIATIVE CONSTITUTIONAL AMENDMENT AND STATUTE. Imposes 5% tax on certain taxpayers with assets over $1 billion; revenue primarily for health care. Exempts revenues from constitutional requirements for school funding and spending limit. Fiscal Impact: Temporary revenue increase of tens of billions of dollars spread over several years from wealth tax on billionaires. Possible ongoing decrease of less than $1 billion per year in income tax revenue from billionaires.
Source: California Secretary of State
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Proposition 40 news
October 1, 2026October 1, 2026
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