Revenue and taxation; income tax; rate; effective date.

HB 1209 modifies Oklahoma's individual income tax structure for tax years beginning in 2024 and 2026. For 2024-2025, it lowers the top marginal tax rate from 5.5% to 4.75% for both single filers and married couples filing jointly, while reducing rates across all income brackets (e.g., 0.25% on the first $1,000 for singles instead of 0.5%). The bill also eliminates the deduction for federal income taxes paid when calculating Oklahoma taxable income. This directly affects all Oklahoma residents and nonresidents filing state income tax returns. The 2026+ tax rates are referenced but not fully detailed in the provided text.