According to the Tax Foundation, forty-three states made significant changes in their tax codes this year, with three states reducing their corporate income tax rates. Effective January 1, 2026, the changes noted below underscore healthy tax competition across states. Some other notable updates include: Arkansas continuing to phase out its throwback rule, adopting market-based sourcing, and enacting an economic nexus threshold for nonresident corporations; Delaware S corporations officially decoupling from Sections 168(k) and 168(n), which relate to expensing for machinery and equipment for certain structures; Louisiana phasing out of its capital stock tax; and Mississippi continuing its phasedown of its own capital stock tax.
To see more adjustments and to get a more thorough picture of this year’s state tax updates, visit www.taxfoundation.org/research/all/state/2026-state-tax-changes.
Source: Nicole Fox and Jacob Macumber-Rosin, “State Tax Changes Taking Effect January 1, 2026,” Tax Foundation, December 18, 2025, https://taxfoundation.org/research/all/state/2026-state-tax-changes.
