California policymakers are flirting with an idea that’s sparking debate: a one‑time 5% tax on the net worth of its billionaires. The so-called “wealth tax” is intended to raise tens of billions for health care and other public services in the Golden State.
The proposal, backed by the Service Employees International Union–United Healthcare Workers West (SEIU‑UHW) and Congressman Ro Khanna (D-Ca.-17), but opposed by California Gov. Gavin Newsom, would apply to individual residents with more than $1 billion in wealth as of January 1, 2026.
The measure is currently in the signature-gathering phase and is structured as a single levy rather than an ongoing annual tax. But if voters approve it, the measure would be retroactive, potentially taxing existing fortunes.
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That unusual approach is raising questions and sparking controversy. Here’s more of what you need to know.
How the California billionaire tax would work
Under the proposed “2026 Billionaire Tax Act,” any California resident whose net worth exceeds $1 billion calculated as of December 31, 2026, would owe 5% of that net worth, with payment due in 2027.
The proposal reportedly includes a phase-out between $1 billion and $1.1 billion in net worth, meaning individuals just over the threshold wouldn’t face the full 5% rate immediately.
- Those who cannot or do not want to pay in full could spread payments over five years, but remaining balances would incur an additional annual, nondeductible charge.
- The tax base could affect businesses, stocks, bonds, art, collectibles, and intellectual property, while excluding real estate, pensions, and retirement accounts.
Advocates note that the idea is to focus on types of financial and corporate wealth that have surged in recent years, e.g., in the tech industry.
California’s nonpartisan Legislative Analyst’s Office has estimated that roughly 200 to 250 billionaires could be affected by the measure and that the plan could raise approximately $100 billion in one-time revenue.
However, those estimates and any final numbers would depend heavily on stock market performance and whether ultra‑wealthy residents remain in the state.
Pushback from prominent lawmakers
Not surprisingly, the plan has drawn sharp resistance from some high‑profile lawmakers. A key concern seems to be the potential for driving capital and high-earning residents away.
Gov. Gavin Newsom has said these kinds of wealth‑tax ideas are “going nowhere in California” and argued the state “can’t isolate [itself] from 49 other states.”
San Jose’s Democratic mayor, Matt Mahan, warned on X that “driving billionaires out of state might feel good in the short run but working people (as is almost always the case) will pick up the tab,” for what he described as a “political policy.”
- Mahan has pointed out that roughly half of California’s personal income tax revenue comes from the top 1% of earners.
- The argument is that if those taxpayers leave, the state could be forced either to raise taxes on the middle class or cut services.
The proposal has also sparked opposition funding. Billionaire and Palantir co-founder Peter Thiel is reportedly donating $3 million to the California Business Roundtable to try to defeat it.
California billionaires: Split with NVIDIA CEO
But notably, not all billionaires oppose the measure.
NVIDIA CEO Jensen Huang, whose estimated net worth of $155-162 billion would subject him to a roughly $8 billion tax bill, said he is “perfectly fine” with the proposal.
“We chose to live in Silicon Valley, and whatever taxes they would like to apply, so be it,” Huang recently told Bloomberg Television. “I’ve got to tell you, I have not even thought about it once.”
Huang emphasized that Silicon Valley’s talent pool is the primary reason NVIDIA remains in California.
Adding to the chatter, late last year, in response to Thiel’s warning of a departure from the state due to such a tax, Congressman Khanna posted the following on X (formerly Twitter).
“Peter Thiel is leaving California if we pass a 1% tax on billionaires for five years to pay for healthcare for the working class facing steep Medicaid cuts. I echo what [former President Franklin D. Roosevelt] said with sarcasm of economic royalists when they threatened to leave, ‘I will miss them very much.'”
Taxing unrealized gains?
Some of what adds to the debate over this proposal is the idea that it could effectively tax unrealized gains — the paper increase in value of assets that haven’t been sold.
- Note: Under current federal rules, most capital gains are taxed only when an asset is sold, so the owner has cash to pay the tax.
- Here, if approved, the state would look at what someone is worth on a set date and apply 5% to that amount, whether or not any stock, business stake, or artwork has been converted to cash.
Critics say that could force founders and investors to unload big slices of companies or other illiquid assets to pay the bill. The argument is that it could potentially drag down valuations and affect ordinary shareholders.
Supporters counter that the current system lets billionaires’ wealth soar while reporting relatively modest taxable income. A one‑time wealth tax is seen by some as a way to reach gains that otherwise might never be taxed.
Legal and practical questions
The wealth tax proposal includes language to amend the California constitution so the levy fits within existing limits. But legal pundits disagree on whether a one‑time tax on overall net worth would be treated, from a legal standpoint, (i.e., more like a property tax, a capital gains tax, or something else).
That uncertainty means lawsuits are almost guaranteed, even if voters sign off on the measure.
From a practical standpoint, the state would also have to determine the value of highly complex assets on the key valuation date.
- For example, stakes in private companies, venture funds, or unique art and intellectual property could be harder to price and easier to dispute.
- California tax authorities would need detailed valuation rules and substantial enforcement resources.
- Wealthy taxpayers would likely challenge aggressive assessments, which some say could slow collections and add cost.
What’s at stake for California taxpayers
For individual taxpayers, the question is not whether they personally will owe the tax, since this plan is aimed at a small number of residents. The key question is whether a billionaire tax would improve the lives of everyone in the state.
Supporters believe that a one-time large contribution could reduce the burden on other taxes and offset federal funding cuts.
- The funds from this levy would pay for healthcare and related services without increasing income or sales taxes for middle- and lower-income families.
- Essentially, they argue that a small portion of the wealthy’s fortunes can help support systems that everyday families depend on.
Opponents are concerned that if many wealthy individuals move away or transfer their assets, the state could lose significant tax revenue.
- This would mean higher taxes for those who stay or cuts to services.
- They also warn that forced asset sales could disrupt the market, affecting anyone with a retirement account linked to those companies.
Bottom line? California voters could ultimately decide, but the proposal requires about 874,000 signatures to reach the November 2026 ballot. So, stay tuned.
