AZ SB1057

Amends Arizona's definition of "Internal Revenue Code" to conform to the federal Internal Revenue Code of 1986 as amended and in effect on January 1, 2024 for taxable years beginning after December 31, 2023.

Updates Section 42-1001 to change the reference date from January 1, 2023 to January 1, 2024 for determining which federal tax code provisions Arizona will recognize.

Adds a new subsection in Section 43-105 establishing that for taxable years beginning after December 31, 2023, Arizona will use the federal code as of January 1, 2024, including retroactively effective provisions from 2023.

Modifies the prior year provision (now subsection B) for taxable years between December 31, 2022 and December 31, 2023 to include retroactively effective provisions during that period.

Renumbers existing subsections in Section 43-105 to accommodate the new 2024 provision, maintaining conformity rules for all prior taxable years back through 2013.