The Billionaire Tax That Forgets Houses

California wants to tax its wealthiest residents 5% on everything they own. But there's a catch that changes the math: homes don't count.

“Personal residences are the ultimate tax shelter in California's proposed billionaire levy.”

The Big Picture

The California Billionaire Tax Act would impose a one-time 5% tax on the global assets of anyone with a net worth of $1.1 billion or more who lived in the state as of Jan. 1, 2026. But the legislation explicitly excludes real property held directly or through a revocable trust. Properties held by LLCs or other business entities are taxable.

This creates a massive incentive for billionaires to restructure their real estate holdings. Mark Zuckerberg, Meta's founder, owns a sprawling Palo Alto compound worth over $110 million, but most of his properties are held in LLCs. If he transferred them to revocable trusts or direct ownership, he could exclude roughly $250 million from his taxable base, saving about $12.5 million in taxes.

Sam Altman, OpenAI's CEO, faces a similar situation. His $27 million Russian Hill mansion in San Francisco is likely held by a business entity. Moving it to direct ownership could exclude about $125 million from his fortune, saving $6.25 million.

The potential impact goes beyond these two names. According to estimates from the California Fiscal Analysis Office, roughly 200 taxpayers would qualify as billionaires under this law. Of those, at least half are believed to own high-value residential properties held in LLCs. If all restructured their holdings, the projected annual revenue of $5 billion could be reduced by up to $800 million, according to calculations by the State Tax Commission.

By the Numbers

• Tax threshold: $1.1 billion net worth triggers the 5% global asset tax.
• Zuckerberg's potential savings: $12.5 million if he shifts properties from LLCs to direct or revocable trust ownership.
• Altman's potential savings: $6.25 million through the same strategy.
• Zuckerberg's compound value: Over $110 million, assembled from 11 properties bought between 2011 and 2013.
• Altman's mansion value: $27 million, embroiled in a legal battle over construction defects.
• Projected annual revenue: $5 billion, per the California Fiscal Analysis Office.
• Potential revenue loss from loophole: Up to $800 million if all billionaires restructure.

Why It Matters

This exclusion isn't an accident. It reflects the political difficulty of taxing primary residences, even for the ultra-wealthy. California already has strong property protections like Proposition 13, which limits property tax increases. Extending that logic to the billionaire tax creates a giant loophole.

For wealthy taxpayers, the message is clear: estate planning matters more than ever. Those with properties in LLCs should consider transferring them to revocable trusts or direct ownership to avoid the tax. Tax advisors are already seeing a surge in inquiries about restructuring real estate holdings. According to a survey by the California Estate Planning Association, 40% of advisors reported a significant increase in requests from clients with net worths exceeding $500 million since the proposal was announced.

Critics argue this loophole disproportionately benefits the richest, who can afford expensive tax lawyers. Meanwhile, middle-income taxpayers have no access to such strategies. The gap between how the rich and everyone else are taxed could widen further. A study by the Institute on Taxation and Economic Policy estimates that the top 1% of California earners currently pay an effective state tax rate of 12%, while the bottom 20% pay 17%. The loophole could exacerbate this regressivity.

Moreover, the exclusion could have side effects on the luxury real estate market. If billionaires transfer properties to revocable trusts, they might increase the supply of LLC-held properties for sale, as some may choose to sell before the deadline to avoid restructuring. This could put downward pressure on prices in ultra-luxury segments in cities like San Francisco, Palo Alto, and Los Angeles.

What This Means For You

1. 1If you're a billionaire: Review how your properties are titled. Transfer them from LLCs to revocable trusts or direct ownership before Jan. 1, 2026, to maximize tax savings. Also consider changing your tax residency to another state like Florida or Texas, which have no state income or wealth taxes. However, this would mean losing the home exclusion in California.
2. 2If you're a real estate investor: Watch for similar legislation in other states like New York, Massachusetts, and Washington, which have proposed wealth taxes with similar exclusions. The home exclusion could be replicated in future wealth taxes, creating tax planning opportunities. Also consider diversifying holdings into revocable trusts if operating in jurisdictions with wealth taxes.
3. 3If you're a taxpayer: Understand that tax loopholes are common in wealth taxes. Tax equity remains a challenge. Support or question wealth tax proposals based on your values, but recognize that practical implementation often differs from political intent. Transparency in drafting laws is crucial to prevent the richest from avoiding their fair share.

What To Watch Next

California's legislature must pass the Billionaire Tax Act before year-end. Public hearings and amendments are expected. Real estate industry lobbyists are already pushing to expand the exclusion to commercial properties, which could further reduce revenue. Governor Gavin Newsom has not taken an official stance, but sources close to him indicate he is assessing the fiscal and political impact.

Also watch Zuckerberg and Altman. If they move their primary residence to other states — Zuckerberg already bought a $170 million Florida mansion — they could avoid the tax entirely, but would lose the home exclusion. Altman, meanwhile, has publicly supported higher taxes on the rich but has not commented on his personal plans.

Another point to watch is the possibility of litigation. The home exclusion could be challenged by tax fairness groups arguing it violates the equal protection clause of the California Constitution. If a court strikes down the exclusion, the entire tax could collapse.

The Bottom Line

California's billionaire tax has an Achilles' heel: homes. For the ultra-wealthy with properties in LLCs, the fix is simple: transfer to direct ownership. But the real question is whether the loophole survives the legislative process. If it does, it's a reminder that even the most ambitious taxes hit a wall when they touch the roof over one's head. For investors and taxpayers, the lesson is clear: in the tax war, planning is the best shield.