This bill, known as the "SLUSH FUND Act of 2026," amends the Internal Revenue Code to impose a 100 percent tax on specific settlement payments. This tax applies to amounts received by former U.S. Presidents, their family members, or entities they control, when these payments originate from civil actions against the United States government or its agencies. These "specified settlement fund payments" are explicitly excluded from a taxpayer's gross income for regular income tax purposes, meaning they are solely subject to this new, high tax rate. The legislation mandates that fiduciaries making such payments must file returns with the Secretary of the Treasury, detailing the amounts and recipients. A key provision requires the Secretary to make these filed returns publicly available within one month, enhancing transparency. To enforce compliance, the bill establishes a 50 percent penalty for taxpayers who willfully fail to pay or attempt to evade this tax. Additionally, fiduciaries face a $10,000 penalty for each failure to file the required reporting returns. These new tax and reporting requirements are effective for amounts received or paid on or after May 20, 2026.