The Environmental Protection Agency (EPA) is finalizing requirements that state, local and tribal air agencies would have to meet as they implement the current and future national ambient air quality standards (NAAQS) for fine particulate matter (PM<INF>2.5</INF>). Specifically, this document provides details on meeting the statutory state implementation plan (SIP) requirements that apply to areas designated nonattainment for any PM<INF>2.5</INF> NAAQS, such as: General requirements for attainment plan due dates and attainment dates; emissions inventories; attainment demonstrations; provisions for demonstrating reasonable further progress; quantitative milestones; contingency measures; and nonattainment New Source Review (NNSR) permitting programs, among other things. This rule clarifies the specific attainment planning requirements that apply to PM<INF>2.5</INF> NAAQS nonattainment areas based on their classification (either Moderate or Serious), and the process for reclassifying Moderate areas to Serious. Additionally, in this document the EPA is revoking the 1997 primary annual standard for areas designated as attainment for that standard because the EPA revised the primary annual standard in 2012. The EPA first established the PM<INF>2.5</INF> NAAQS in 1997, completed a review and revision of those standards in 2006, and most recently completed a review and revision of the PM<INF>2.5</INF> NAAQS on December 14, 2012.