On October 21, 2025, the 2026 Billionaire Tax Act was filed with the California Attorney General’s office. The proposed initiative, if enacted, will impose a one-time 5% excise tax on California residents with net wealth in excess of $1 billion, to be paid April 15, 2027.
Proponents of the measure will begin circulating it for signatures in an effort to qualify it for the November 2026 California ballot. They need to gather roughly 900,000 verifiable signatures to be successful.
The proposed ballot measure, if passed, would impact California resident individuals, whether single or married, with a net worth over $1 billion in 2026. The proposed measure would also impact trusts with California resident beneficiaries that cross the same net worth threshold. The measure, if passed by the voters, would be retroactive to January 1, 2026.
Under the terms of the proposed ballot measure, net worth would be determined by taking the fair market value of all assets owned by the taxpayer, including assets held in grantor trusts, with limited exceptions. The proposed measure is explicit that a forced sale price or sale price in a market outside of the normal channels, such as selling silver on a coffee exchange, would not count for determining market value. Instead, the burden would be upon the taxpayer to demonstrate the fair market value of each of their assets to the satisfaction of the Franchise Tax Board.
Notably, interests in real property, whether held directly or through a trust, and certain retirement accounts are excluded for determining net worth for purposes of the potential tax. The proposed measure would also exclude tangible personal property located outside of California for more than 270 days in 2026 so long as the purpose was not to avoid tax.
The assets to measure would include stock, partnerships, interests in business entities, any equity interests, ownership interests, debt interests, and “all other contractual or noncontractual interests” the taxpayer may own.
The proposed ballot measure would seek to limit the availability of discounts if they have the effect of reducing the value of a partial interest in an asset below the taxpayer’s pro-rata portion of the asset’s entire value.
Charitable or philanthropic pledges would not reduce net worth if they were made after October 15, 2025. Similarly, only certain types of debt instruments would reduce net worth.
There would be substantial penalties for non-compliance and understatement of net worth in the proposed measure. If the proposed ballot measure passes, it would provide for the California legislature to make changes they see fit after passage.
To learn more about the proposed ballot measure, please contact your firm professional.
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