taken from USCIS site.
Currently, foreign students in F-1 nonimmigrant status who have been enrolled on a full-time basis for at least one full academic year in a college, university, conservatory, or seminary certified by U.S. Immigration and Custom Enforcement's (ICE's) Student and Exchange Visitor Program (SEVP) are eligible for 12 months of optional practical training (OPT) to work for a U.S. employer in a job directly related to the student's major area of study. This interim final rule extends the maximum period of OPT fro m 12 months to 29 months for F-1 students who have completed a science, technology, engineering, or mathematics (STEM) degree and accept employment with employers enrolled in U.S. Citizenship and Immigration Services' (USCIS') E-Verify employment verification program. This interim rule requires F-1 students with an approved OPT extension to report changes in the student's name or address and changes in the employer's name or address as well as periodically verify the accuracy of this reporting information. The rule also requires the employers of F-1 students with an extension of post-completion OPT authorization to report to the student's designated school official (DSO) within 48 hours after the OPT student has been terminated from, or otherwise leaves, his or her employment with that employer prior to end of the authorized period of OPT.
This rule also ameliorates the so-called ``cap-gap' problem by extending the authorized period of stay for all F-1 students who have a properly filed H-1B petition and change of status request (filed under the cap for the next fiscal year) pending with USCIS. If USCIS approves the H-1B petition, the students will have an extension that enables them to remain in the United States until the requested start date indicated in the H-1B petition takes effect. This interim final rule also implements a programmatic change to allow students to apply for OPT within 60 days of concluding their studies.