MARK-TO-MARKET TAX ACT Senate SponsorsSen. Karina Villa-Graciela Guzmán, Rachel Ventura, Javier L. Cervantes, Adriane Johnson, Mark L. Walker, Ram Villivalam, Mattie Hunter and Lakesia Collins 2/4/2026SenateReferred to Assignments New Act35 ILCS 5/203from Ch. 120, par. 2-203Creates the Extremely High Wealth Mark-to-Market Tax Act. Provides that a resident taxpayer with net assets worth $1,000,000,000 or more shall recognize gains or losses as if each asset owned by that taxpayer had been sold for its fair market value on December 31 of the taxable year. Contains provisions concerning the calculation of the amount of tax due from those gains or losses. Amends the Illinois Income Tax Act to make conforming changes. Effective immediately. 2/4/2026SenateFiled with Secretary by Sen. Karina Villa 2/4/2026SenateFirst Reading 2/4/2026SenateReferred to Assignments 2/9/2026SenateAdded as Co-Sponsor Sen. Rachel Ventura 2/25/2026SenateAdded as Co-Sponsor Sen. Javier L. Cervantes 2/26/2026SenateAdded as Co-Sponsor Sen. Adriane Johnson 2/27/2026SenateAdded as Chief Co-Sponsor Sen. Graciela Guzmán 2/27/2026SenateAdded as Co-Sponsor Sen. Mark L. Walker 3/5/2026SenateAdded as Co-Sponsor Sen. Ram Villivalam 3/10/2026SenateAdded as Co-Sponsor Sen. Mattie Hunter 3/11/2026SenateAdded as Co-Sponsor Sen. Lakesia Collins