IL SB3884

Creates the Extremely High Wealth Mark-to-Market Tax Act requiring Illinois residents with net assets of $1 billion or more to recognize annual gains or losses as if all assets were sold at fair market value on December 31, with gains capped at 25% of assets exceeding $1 billion.

Increases the corporate income tax rate from 7% to 9% for taxable years beginning on or after January 1, 2027.

Directs the Department of Commerce and Economic Opportunity to develop a child care assistance program with subsidies and benchmarks to limit family co-payments to no more than 7% of income by 2030.

Expands child care subsidy eligibility through a phased approach reaching families earning up to 250% of state median income, with automatic eligibility for Medicaid and WIC recipients.

Allows billionaire taxpayers to pay the mark-to-market tax in one lump sum or in 10 annual installments with a 7.5% annual deferral charge, effective immediately upon enactment.