Updates
Updates include calculation and rate changes to reflect current tax law resulting from inflation adjustments, legislative changes, and review of supported authorities.
Effective dates indicate when the changes enter into force. Updates are effective January 1 unless stated otherwise.
Amounts are given in USD. Amounts are annual unless stated otherwise.
United States – 2024
Arkansas
Made the following changes:
Decreased the top bracket rate by 0.5% to 3.9%.
Increased the bracket adjustment threshold by $1,900 to $92,700.
California
Increased the following for all filing status based on CPI changes:
Bracket thresholds. The threshold for the 12.3% top bracket increased by $23,042 to $721,313 for single employees. An additional 1% tax is imposed on income over $1 million.
Standard deductions and exemption credits.
Phaseout threshold for itemized deductions and exemption credits.
Iowa
Corrected the calculation to use federal taxable income. Previously, the state taxable income was decreased by federal tax paid, resulting in a possible understatement of tax costs.
Kansas
Made the following changes for all filing status:
Decreased the number of tax brackets from three to two and updated rates. The threshold for the new 5.58% top bracket is $23,000 for single employees.
Increased the personal exemption. The amount for single employees increased by $6,910 to $9,160.
Increased the standard deduction. The amount for single employees increased by $105 to $3,605.
Increased the dependent exemption by $70 to $2,320.
Louisiana
Updated the supplemental tax calculation from a 4.25% flat rate to a three-tiered progressive table with a 5.05% top bracket rate on income over $50,000.
Maryland
Corrected the supplemental tax calculation from a four-tiered progressive table with a 5.75% top bracket rate to a 5.75% flat rate.
Massachusetts
Updated the supplemental tax calculation from a 5% flat rate to a two-tiered progressive table with a 9% top bracket rate on income over $1.05 million.
North Dakota
Corrected the supplemental tax rate by decreasing it from 0.34% to 1.5%.
Ohio
Updated the supplemental tax calculation from a 3.5% flat rate to a six-tiered progressive table with a 4.41% top bracket rate on income over $100,000.
South Carolina
Decreased the supplemental and top statute rates by 0.2% to 6.2%.
United States – 2025
Iowa
Made the following changes:
Updated the statute tax calculation from a three-tiered progressive table with a 5.7% top bracket rate to a 3.8% flat rate.
Decreased the supplemental rate by 2.2% to 3.8%.