TAXATION – Amends existing law to update references to the current Internal Revenue Code and to revise certain tax credits and adjustments.

This Idaho bill updates the state's tax code to align with the current Internal Revenue Code (IRC), specifically revising how businesses calculate taxable income related to depreciation and research credits. It directly affects Idaho businesses and taxpayers claiming bonus depreciation or research activity credits, ensuring adjustments prevent double tax benefits when federal loss limitations apply. Key provisions include modifying how bonus depreciation deductions are handled for Idaho tax purposes (e.g., adding back unused federal depreciation when losses are later deducted) and updating research credit rules for activities conducted in Idaho. The changes apply retroactively to certain tax years and require businesses to track Idaho-specific tax basis and loss carryforwards.