Income tax; modifying marginal income tax brackets for certain tax years. Effective date.

SB 327 modifies Oklahoma's individual income tax brackets for specific tax years, affecting all Oklahoma residents and nonresidents who file state income tax returns. It adjusts the tax rates applied to income above certain thresholds, particularly changing the rate on the "remainder" of taxable income from 6.75% (for 1999-2001) to 6.65% (for 2004 and later) for both single filers and married couples filing jointly. The bill updates the statutory language in Section 2355 of Oklahoma's tax code to reflect these rate changes for tax years beginning after December 31, 1998, and before January 1, 2006. This is a substantive tax rate adjustment, not a procedural change, and it updates the legal reference for future compliance. The bill amends the existing tax structure without creating new tax categories.