Judicial Administration and Improvement Act of 2017 This bill divides the U.S. Court of Appeals for the Ninth Circuit into: (1) a new Ninth Circuit, to be composed of California, Hawaii, Oregon, Guam, and the Northern Mariana Islands; and (2) a newly established Twelfth Circuit, to be composed of Alaska, Arizona, Idaho, Montana, Nevada, and Washington. Precedent from the former Ninth Circuit shall not be binding on the Twelfth Circuit. The bill designates locations where the new circuits are to hold regular sessions. The bill distributes active circuit judges of the former Ninth Circuit to the new circuits. Circuit judges and senior circuit judges currently stationed in Alaska, Arizona, Idaho, Montana, Nevada, or Washington may elect their circuit assignment. For each circuit judge in regular service who elects to be assigned to the new Ninth Circuit, the President shall appoint one additional circuit judge for the Twelfth Circuit.