internal revenue code; conformity.

Arizona updates federal rules for state taxes

For tax years starting after December 31, 2024, Arizona uses federal income tax rules in effect on January 1, 2025. This includes provisions effective during 2024 with retroactive dates, but excludes federal changes enacted after January 1, 2025. For tax years starting after December 31, 2023, through December 31, 2024, Arizona uses the January 1, 2024 rules. Later federal changes count for those tax years only when they take effect retroactively during those years. These rules can raise or lower a taxpayer’s Arizona income tax bill; the law sets no new rates or credits.