Optional Practical Training (OPT) is a period during which undergraduate and graduate students with F-1 status who have completed or have been pursuing their degrees for more than nine months are permitted by the United States Citizenship and Immigration Services (USCIS) to work for at most one year on a student visa towards getting practical training to complement their field of studies. F-1 students are usually permitted a total of 12 months of practical training. On April 2, 2008, the U.S. Department of Homeland Security (DHS) Secretary Michael Chertoff announced a 17-month extension to the OPT for students in qualifying STEM fields. To be eligible for the 12-month permit, any degree in any field of studies is valid. For the 17-month OPT extension, a student must have received a Science, Technology, Engineering, or Mathematics degree in one of the following approved majors listed on the USCIS website. This new interim final rule provides a permanent solution to the H-1B "cap-gap", when an academic foreign student's (F-1) status and work authorization expire during the current fiscal year before the student can start approved H-1B employment during the next fiscal year beginning on October 1. Previous cap-gap provisions extended only the stay but not the employment authorization. On May 31, 2008, the Immigration Reform Law Institute filed a lawsuit in federal court on behalf of various organizations and individuals challenging the validity of the 17 month OPT extension.