The measure, which voters are scheduled to consider Nov. 3, would impose a one-time 5% tax on the wealth of California residents whose net worth exceeds $1 billion. It would apply to people whose primary residence was in the state on Jan. 1, 2026.

Zuckerberg’s fortune is estimated at more than $220 billion. At that level, the tax could exceed $11 billion, based on the proposal’s rate and his estimated wealth.

Meta’s board approved a new class of non-voting shares that Zuckerberg may sell for any reason, including to pay a potential tax bill. The shares represent 10% of his overall economic stake, while the arrangement is structured to keep him the company’s majority owner.

The agreement follows Zuckerberg’s consideration last month of selling his Palo Alto home in response to the proposed tax. He has now committed to remain in California for eight years, unless unforeseen circumstances make it advisable for him to live elsewhere, the filings say.

The proposal would send most of its revenue toward replacing federal health care funding cuts. The remaining 10% would support education and food-assistance programs. Supporters, including SEIU United Healthcare Workers West and U.S. Sen. Bernie Sanders, say the tax would require the wealthiest Californians to contribute more.

Opponents, including Gov. Gavin Newsom, have warned that wealthy residents could leave, potentially reducing the state’s income-tax revenue. California depends heavily on income taxes paid by its highest earners, making the potential effects on state finances a central point of debate.

The Legislative Analyst’s Office estimates that a few hundred billionaires live in California. Meanwhile, a committee opposing the tax and backing measures intended to block it, Building a Better California, has raised more than $333 million, including 30% from Google co-founder Sergey Brin. The campaign supporting the tax has raised $32.7 million.

Brin and Google co-founder Larry Page have taken steps to reduce their ties to California, while Zuckerberg’s agreement offers a different approach: using company shares to meet a potential tax obligation while remaining in the state.

Zuckerberg has received a $1 annual salary as Meta’s CEO since 2013. Meta said in the filings he would receive no additional compensation and argued that, if the tax passes, he would effectively be paying to serve as CEO while living in California. The company also said the new shares could help fund employee compensation, acquisitions and investments in artificial-intelligence infrastructure.

Meta Chief Financial Officer Susan Li said the shares would broaden the company’s funding options and provide flexibility for investment.