Proposition 40 — billionaire wealth tax

What a YES vote does

YES imposes a one-time 5% tax on certain billionaires' assets to fund health care and other services.

Official vote explanation, November 2026 edition; publication day unstated; retrieved 2026-10-05.

What a NO vote does

NO rejects this one-time tax on billionaires' wealth.

Official vote explanation, November 2026 edition; publication day unstated; retrieved 2026-10-05.

Cost and money

The current official analysis estimates tens of billions of dollars over several years, and possible ongoing income-tax revenue losses of less than $1 billion annually.

Exact receipts and behavioral effects are uncertain.

Official fiscal analysis, November 2026 edition; publication day unstated; retrieved 2026-10-05.

Who put it on the ballot

Initiative petition; certified June 25, 2026.

Official qualified list, undated, retrieved 2026-10-05; Secretary Shirley Weber's certification release, 2026-06-25. Weber is the certifying official, not the measure's sponsor. June 25 is certification, not a claim that every legislative vote occurred that day.

A rule that matters

The tax reaches defined assets of affected billionaires and dedicates most proceeds to health care.

Competing Propositions 41 and 42 could limit its implementation; the legal result depends on voter approval and the conflict provisions.

Official analysis and law, November 2026 edition; publication day unstated; retrieved 2026-10-05.

Who is paying

SOS daily chart: Yes $32,565,406.00; No $84,770,000.00. Quick Guide, undated daily snapshot retrieved 2026-10-05. The chart applies election-cycle/allied-transfer adjustments. Committee exports below use their own records and may include later receipts, shared campaigns, intermediary money and nonmonetary support. Differences remain unreconciled; do not add them or treat the chart as a committee balance.

Yes: Yes on 40 - Billionaire Tax Now – No on 41 & 42, Sponsored by Service Employees International Union - United Healthcare Workers West, #1484470

$32,423,797.91 in captured itemized receipts. Periodic records through 2026-09-19: $31,847,564.50; added later receipts: $576,233.41. Cal-Access filer #1484470, late receipts, retrieved 2026-10-05.

Shared committee: these are committee-wide receipts across propositions 40, 41, 42. They are not allocated to this proposition, and must not be added again across measure pages.

Captured periodic export; captured late export. Aliases combine only where a contributor ID matches; negative adjustments remain negative. Named affiliated groups may appear separately.

No: Stop the Squeeze

$400,000.00 in captured itemized receipts. Periodic records through 2026-03-06: $400,000.00; added later receipts: $0.00. Cal-Access filer #1485007, late receipts, retrieved 2026-10-05.

Only 3 positive donor identities appear in the captured itemized records; no extra names invented.

Captured periodic export; captured late export. Aliases combine only where a contributor ID matches; negative adjustments remain negative. Named affiliated groups may appear separately.

No: Californians Against Tax Increases, sponsored by the California Business Roundtable - No on 40

$250,000.00 in captured itemized receipts. Periodic records through 2026-03-10: $220,000.00; added later receipts: $30,000.00. Cal-Access filer #1485228, late receipts, retrieved 2026-10-05.

Only 2 positive donor identities appear in the captured itemized records; no extra names invented.

Captured periodic export; captured late export. Aliases combine only where a contributor ID matches; negative adjustments remain negative. Named affiliated groups may appear separately.

No: Golden State Promise,1486695

$10,450,000.00 in captured itemized receipts. Periodic records through 2026-06-18: $10,450,000.00; added later receipts: $0.00. Cal-Access filer #1486695, late receipts, retrieved 2026-10-05.

Only 3 positive donor identities appear in the captured itemized records; no extra names invented.

Captured periodic export; captured late export. Aliases combine only where a contributor ID matches; negative adjustments remain negative. Named affiliated groups may appear separately.

No: No on Prop 40 - Doctors, Teachers, Small Businesses, Working Families and Public Safety Against the Reckless Wealth Tax Experiment, #1492108

$88,721,279.44 in captured itemized receipts. Periodic records through 2026-09-18: $56,721,279.44; added later receipts: $32,000,000.00. Cal-Access filer #1492108, late receipts, retrieved 2026-10-05.

Only 4 positive donor identities appear in the captured itemized records; no extra names invented.

Captured periodic export; captured late export. Aliases combine only where a contributor ID matches; negative adjustments remain negative. Named affiliated groups may appear separately.

Why: who benefits

Funded health services can benefit; affected billionaires bear the tax.

The Yes committee is sponsored by SEIU-UHW, while a major No committee receives Building a Better California transfers. These interests align with budget and tax exposure but do not prove personal motives.

Official law and analysis, November 2026 edition; publication day unstated; retrieved 2026-10-05; committee/interest declarations and dated receipts above. Endorsement claims are identified as claims in the official arguments. The published arguments are the signers' opinions, not agency-verified findings.

Existing database, checked 2026-10-05: Secretary of State organization #15343; Shirley Weber politician #100 (certification role only). Funder rows above link the recorded find and resolve results, including exact entity IDs. Near matches were not merged; profiles and prior evidence are leads, not proof about this measure. Lookup custody.

Our view — opinion

What remains unknown

Money received after the captured filings, unfiled late receipts, unitemized donor detail, ultimate sources behind intermediaries, and a full reconciliation between SOS adjusted totals and gross committee receipts remain unknown. Donor rankings aggregate captured receipts within a committee; they do not rank ultimate wealth owners. Loans are identified separately where available.