The Environmental Protection Agency (EPA) is taking interim final action to stay, for emissions sources in California, Illinois, Indiana, Maryland, Michigan, New Jersey, New York, Ohio, Pennsylvania, Virginia, and Wisconsin, the effectiveness of the requirements established to address the obligations of these and other states to mitigate interstate air pollution with respect to the 2015 national ambient air quality standards (NAAQS) for ozone (the Good Neighbor Plan). The EPA is also revising certain other regulations to ensure the continued implementation of previously established requirements to mitigate interstate air pollution with respect to other ozone NAAQS while the effectiveness of the Good Neighbor Plan's requirements is stayed. The stay and the associated revisions to other regulations are being issued in response to a judicial order staying enforcement of the Good Neighbor Plan as to the stay applicants pending judicial review.