The Office of Information and Regulatory Affairs (OIRA) within the Office of Management and Budget (OMB) released the final revised edition of Circular A-4 on November 9, 2023. Accompanied by an Explanation and Response to Public Input, this updated version replaces the original Circular A-4 from 2003 under Executive Order 14094, titled "Modernizing Regulatory Review." Effective March 1, 2024, the revised Circular A-4 will apply to all proposed, direct, and interim final rules. It will extend its applicability to other final rules starting January 1, 2025.
The Regulatory Studies Center of George Washington University published a comparison between the draft Circular A-4 from April 6, 2023, and the final Circular A-4. You can find it here.