Prop 40

Extracted Attributes

• Sponsor

  SEIU United Healthcare Workers West (SEIU-UHW)

• Measure Type

  Initiated constitutional amendment and state statute

• Valuation Date

  2026-12-31

• Target Taxpayers

  California residents and trusts with a net worth of at least $1 billion (approx. 200–250 taxpayers)

• Alternative Names

  California billionaire tax, California wealth tax

• Proposed Tax Rate

  5 percent (one-time wealth tax)

• Target Revenue Uses

  State healthcare programs (Medi-Cal), food assistance, public education

• Signatures Collected

  Roughly 980,000 signatures

• Official Title / Name

  Proposition 40 (2026 Billionaire Tax Act)

• Residency Assessment Date

  2026-01-01

Timeline

• California Attorney General Rob Bonta issues the official title and summary for the Proposition 40 initiative. (Source: Wikipedia)

  2025-12-01

• Qualifying residency date set under Proposition 40 to assess billionaire taxpayer status. (Source: Kugelman Law / CalBudgetCenter)

  2026-01-01

• Proposition 40 is scheduled to appear on the California statewide general election ballot for voter approval. (Source: Official Voter Information Guide)

  2026-11-03

• Valuation date set under Proposition 40 to calculate the net worth subject to the one-time wealth tax. (Source: Kugelman Law)

  2026-12-31

2026 California Proposition 40

Proposition 40, also known as the California billionaire tax or California wealth tax, is a combined initiated constitutional amendment and state statute that will appear on the November 3, 2026, ballot in the state of California. If approved by voters, the state's billionaires would pay a one-time 5 percent tax on their accumulated wealth. Revenue from the tax would primarily fund state healthcare programs, with a smaller portion going toward food assistance and public education. Proposition 40 was sponsored by the labor union SEIU United Healthcare Workers West.

Web Search Results

• Billionaire Tax Explained: What Proposition 40 Would ...

  ## The Bottom Line on Prop. 40 Prop. 40 is a bold proposal that would create a first-in-the-nation tax on wealth, raising significant — temporary — revenue by taxing the fortunes of California’s more than 250 billionaires. Proponents argue this unprecedented measure is needed to help offset deep federal cuts and protect health care, food assistance, and education for all Californians. Because a wealth tax is untested at a state level in the United States, it carries real uncertainty: courts may strike down the measure or portions of it, conflicting measures could lead to years of litigation, and no one can say how the location decisions of billionaires might change and what that would mean for California’s long-term finances. [...] Prop. 40 aims to address the potential concerns about migration by applying the wealth tax to billionaires who were California residents as of January 1, 2026. This retroactive residency date is likely to be challenged in court. However, if it is upheld, any billionaire leaving after this date would not be able to avoid the tax. Additionally, even billionaires who announced moves out of California before this date may not have sufficiently severed their residency with the state for tax purposes, as the state’s Franchise Tax Board considers many factors when verifying residency status beyond simply whether a filer claims to be resident of another state or has purchased property in another state. [...] Prop. 40 would institute a one-time tax on the worldwide wealth of billionaires. For the purposes of the measure, a billionaire subject to the tax could be an individual, a married couple, or a trust with net worth — as defined by the measure — above $1 billion. There are around 250 billionaires in California, with over $2 trillion in total wealth.1)Forbes tracks the daily wealth of billionaires with its “Real-Time Billionaires” list, and the California-specific data was compiled in connection with Jasper Boll, Emmanuel Saez, and Gabriel Zucman, California Billionaires: Wealth, Taxes, and Wealth Tax Revenue Estimates (NBER Working Paper 35218, May 2026). Note: Saez is an author of Prop. 40.

• Facts on Prop 40 | Yes on 40

  [1] Prop 40 is designed to directly address the ongoing federal healthcare funding cuts, keeping healthcare affordable and accessible for millions.

• 2026 California Proposition 40 - Wikipedia

  | Oakland mayor | | --- | | 1994 1998 2002 2006 2010 2014 2018 2022 2024 (recall) 2025 (sp) | | | Riverside mayor | | --- | | List | | | San Bernardino mayor | | --- | | 2005 2009 2014 2018 2022 | | | Stockton mayor | | --- | | 2008 2012 2016 2020 2024 | | Proposition 40, also known as the California billionaire tax or California wealth tax, is a combined initiated constitutional amendment and state statute that will appear on the November 3, 2026, ballot in the state of California. [...] If approved by voters, the state's billionaires would pay a one-time 5 percent tax on their accumulated wealth. Revenue from the tax would primarily fund state healthcare programs, with a smaller portion going toward food assistance and public education. The initiative was sponsored by labor union SEIU United Healthcare Workers West. ## Background Proposition 40 was drafted by tax law professors Brian Galle of UC Berkeley, David Gamage of the University of Missouri, Darien Shanske of UC Davis, and economist Emmanuel Saez of UC Berkeley. Labor union SEIU United Healthcare Workers West (SEIU-UHW) filed the initiative. In December 2025, state attorney general Rob Bonta issued the official title and summary.

• Proposition 40 | Official Voter Information Guide | California Secretary of State

  CON Prop. 40 is a flawed, one-time tax scheme that hurts our economy, damages our state budget, and contains a loophole exposing all Californians to taxes we can’t afford—but does nothing to lower healthcare costs. No safeguards, no accountability. Join California Teachers Association, California Medical Association, California Children’s Hospital Association, California Professional Firefighters, State Building and Construction Trades Council of California, Democrats and Republicans: NO on 40. ### FOR ADDITIONAL INFORMATION FOR Suzanne Jimenez SEIU-UHW : 5480 Ferguson Drive Los Angeles, CA 90022 : (855) 507-7562 info@YesOn40.com: www.yeson40.com AGAINST Californians to Protect Funding for Schools, Healthcare and Public Safety Info@VoteNoOn40.org: VoteNoOn40.org [...] Skip to Main Content Secretary of State Main Website Elections & Voter Information Feedback California General ElectionNovember 3, 2026 ## Official Voter Information Guide Home Propositions Candidates Justices Quick Reference Guide Voter Information Audio/PDF/Large Print Home » Propositions ## PROP 40 ## IMPOSES ONE-TIME TAX ON CERTAIN TAXPAYERS. INITIATIVE CONSTITUTIONAL AMENDMENT AND STATUTE. ### SUMMARY ### Put on the Ballot by Petition Signatures

• California Billionaire Tax: What Prop 40 Means for You

  Proposition 40, formally the 2026 Billionaire Tax Act, qualified for the November 2026 ballot after supporters gathered roughly 980,000 signatures. If voters approve it, it would impose a one-time wealth tax of 5% on the net worth of California residents, and certain trusts, with a net worth of at least $1 billion. Proponents estimate the measure would affect roughly 200 taxpayers and raise funds directed toward Medi-Cal, food assistance, and public education. Two dates drive the measure. Residency is measured as of January 1, 2026, and net worth is valued as of December 31, 2026. In other words, whether you are subject to the tax turns on your residency at the start of 2026, and the amount turns on what you are worth at the end of it. This is a proposed law, not an enacted one. Voters [...] Kugelman Law Tweet twitterShare linkedinShare facebook The California billionaire tax, Proposition 40 on the November 3, 2026 ballot, proposes a one-time 5% tax on the net worth of state residents worth $1 billion or more. As written, it would reach only a few hundred people. Its real significance for the broader high-net-worth community is what it signals: California is sharpening its focus on wealthy residents and on those who leave. If you have serious wealth in the state, the enforcement climate around residency and valuation is the part to watch. To discuss your exposure with an attorney, call (949) 835-0440. ## What is the California billionaire tax? [...] ### Who has to pay the California billionaire tax? As proposed, Proposition 40 applies to California residents, and certain trusts, with a net worth of at least $1 billion, measured by residency on January 1, 2026 and net worth on December 31, 2026. Proponents estimate roughly 200 taxpayers would be affected. ### Is the billionaire tax a one-time tax or an annual tax? The measure is written as a one-time 5% wealth tax, payable up front or over five years with deferral charges. Supporters call it temporary. Critics question whether it would truly expire. It is proposed law and would take effect only if voters approve it on November 3, 2026. ### Can I avoid the tax by moving out of California?