Proposed rule · 2026-11843

Ozone Reclassification State Implementation Plan Rule

The U.S. Environmental Protection Agency (EPA) is reconsidering certain aspects of the January 2025 final rule entitled State Implementation Plan Submittal Deadlines and Implementation Requirements for Reclassified Nonattainment Areas Under the Ozone National Ambient Air Quality Standards ("January 2025 final rule"). Among other things, the January 2025 final rule codified a policy that certain State Implementation Plan (SIP) requirements for a prior classification remain due upon an area's reclassification to a higher classification. In this proposed action, the EPA is proposing a new interpretation that, upon reclassification, an area is subject only to those requirements in Clean Air Act (CAA) section 182 that are specific to that area's current classification. If finalized, this proposed rule would apply nationwide to all past and future reclassifications associated with the 2008, 2015, and any future ozone National Ambient Air Quality Standards (NAAQS). The EPA is not reconsidering or reopening any other aspect of the January 2025 final rule in this rulemaking and is not addressing the scope of applicable requirements for NAAQS other than the ozone NAAQS.