American Public Health Association v. EPA

Nonprofit organizations and federally recognized Tribes filed a petition for review challenging the U.S. Environmental Protection Agency’s rescission of the Clean Air Act endangerment finding for greenhouse gas emissions from motor vehicles and the repeal of greenhouse gas vehicle emissions standards.

On March 19, 2026, Massachusetts, 24 other states and territories, the District of Columbia, and 12 local governments filed a petition for review challenging the final rule.

On April 16 and 20, petitioners filed two requests asking the court to defer the call for merits briefing proposals until EPA addresses four reconsideration petitions that ask EPA to hold a comment period on modeling and other material on which the final rule relied for its conclusion that regulation of vehicle greenhouse gases would be futile. One request asked that the call for briefing proposals be deferred until at least June 4, 2026 or until EPA decides whether to grant the reconsideration petitions. The other request, by the petitioners in the lead proceeding, requested that the court grant a deferral of 90 days (to July 20, 2026), which they indicated could allow EPA to fully resolve the reconsideration petitions.