The South Coast Air Basin (Basin) is designated as an "extreme" nonattainment area for the 2015 8-hour ozone standard and is required to meet the standard by 2037. On December 2, 2022, South Coast AQMD adopted the 2022 Air Quality Management Plan (AQMP), which provides the blueprint for how the Basin will meet the standard by 2037. While the 2022 AQMP largely fulfilled Clean Air Act requirements for "extreme" nonattainment areas, it did not formally address contingency measure requirements as U.S. EPA was in the process of developing updated contingency measure guidance. The 2022 AQMP committed to address these requirements once new guidance was issued. On December 3, 2024, the U.S. EPA released updated guidance for contingency measures. The South Coast Air Basin Contingency Measure SIP Revision for the 2015 8-Hour Ozone Standard has been developed in response to U.S. EPA's new guidance to satisfy contingency measure requirements in the Basin.