California officials announced on June 18 that a proposed billionaire tax measure has qualified for the November 2026 ballot after verifying more than 874,000 valid signatures, surpassing the required threshold for ballot inclusion [1]. Proponents submitted roughly 1.5 million signatures to qualify the measure, which would impose a one-time 5% tax on residents with a net worth over $1 billion, with a phase-in starting at $1 billion and fully applied at $1.1 billion [1, 2, 3, 4].

The tax is backed primarily by the Service Employees International Union - United Healthcare Workers West. It aims to raise funds for healthcare, education, and food assistance programs across California [1, 2, 3, 4]. The tax would apply retroactively to billionaires who were residents as of January 1, 2026 [4]. Over 200 billionaires in California stand to be affected, collectively holding wealth estimated around $2 trillion [2, 3, 4].

Despite qualifying for the ballot, the initiative faces significant opposition from high-profile billionaires like Google's Sergey Brin, who has spent $82 million campaigning against the tax, Palantir's Peter Thiel, and Larry Page [1, 3, 4]. Some wealthy individuals have reportedly moved assets or declared plans to leave California if the tax passes [1, 3, 4].

Governor Gavin Newsom has strongly opposed the measure, arguing it would damage the state's economy and innovation. He has actively sought to block the tax from reaching the ballot before the June 25 deadline, stating, "I'll do what I have to do to protect the state" [1, 2, 3, 4]. Newsom's opposition has fueled uncertainty over the initiative's fate, as prediction markets showed the chances of the tax appearing on the ballot fall sharply from above 80% to near 35.5% on June 16, then rebounding to about 50% on June 17 [2, 4].

Several traditionally allied labor and progressive groups, including the California Teachers Association and Planned Parenthood affiliates, have also publicly opposed the tax [3, 4].

The deadline for final qualification or potential withdrawal of the billionaire tax initiative is June 25, 2026, when California officials will finalize whether the measure will appear on the ballot this November [1, 2, 3, 4].