This explainer was originally published by our news partners CalMatters. Be prepared for California’s primary: Sign up for CalMatters' free election newsletter and be the first to know when they update the CalMatters 2026 Voter Guide with information on key races.
What does California Proposition 40 do?
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 sponsoring the measure, 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.
What do supporters and opponents say?
- Service Employees International Union-United Healthcare Workers West
- Vermont Sen. Bernie Sanders
- Teamsters California
- AFSCME California
- California Democratic Party
- California Business Roundtable
- California Medical Association
- California Teachers Association
- Planned Parenthood
- California Professional Firefighters
- State Building and Construction Trades
- Crypto executive Chris Larsen
- Venture capitalist Ron Conway
Ballot text
This is how the proposition will appear on the ballot.
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
