Revenue and taxation; retirement benefits; exemption; effective date.

Updated the definition of taxable income and adjusted gross income to include specific rules for interest income from state obligations and deductions prohibited by federal or state constitutions.

Revised net operating loss deduction rules to adjust carryovers and carrybacks based on when the loss was sustained, with different rules for losses before and after 1981.

Changed net operating loss carryover periods to match federal Section 172 rules, with specific exceptions for Oklahoma taxable income terminology.

Updated allocation rules for income from real and tangible personal property, intangible personal property, and partnership interests, including new rules for publicly traded partnerships.

Established different net operating loss carryback periods for different time periods: unlimited for pre-1981 losses, federal rules for 1981-2000, and limited two-year carrybacks for post-2008 losses.