http://www.washingtonpost.com/blogs/the-switch/wp/2014/11/20/ob
There is currently no limit on the number of students who can qualify to
work in the United States under OPT. But Obama could expand the types of
students who qualify to stay for a longer period or further increase the
time-limit on STEM authorizations, perhaps to 48 months, according to
several people involved in the debate.