The "Judicial Administration and Improvement Act of 2025" aims to divide the current Ninth Judicial Circuit of the United States into two distinct circuits, thereby increasing the total number of federal judicial circuits from thirteen to fourteen. This restructuring is intended to reorganize the federal appellate court system in the western United States. Under this legislation, the existing Ninth Circuit would be redefined to include California, Hawaii, Oregon, Washington, Guam, and the Northern Mariana Islands , with an authorized complement of 21 circuit judges. A new Twelfth Judicial Circuit would be established, encompassing Alaska, Arizona, Idaho, Montana, and Nevada , and would be authorized to have 8 circuit judges. The Twelfth Circuit would hold court in designated locations such as Las Vegas, Phoenix, Anchorage, and Missoula. The bill details the assignment of active circuit judges based on their official duty station, with judges from the new Twelfth Circuit's territory having the option to elect assignment to the redefined Ninth Circuit. Senior judges also have an election option for their assignment. To accommodate these elections and maintain judicial capacity, the legislation authorizes temporary judgeships for the Twelfth Circuit. Furthermore, the bill includes provisions for handling cases pending before the former Ninth Circuit, ensuring a smooth transition by either allowing submitted cases to proceed as if no change occurred or transferring unsubmitted cases to the appropriate new circuit. The Act is slated to take effect one year after its enactment, with appropriations authorized to support its implementation and provide necessary facilities.