WASHINGTON (AP) — The government is falling short in assessing the risks of a program that allows tens of thousands of foreign students to stay in the United States and work for close to 2 1/2 years, according to a newly released report from the Government Accountability Office.

The GAO, Congress’ investigative arm, examined the optional practical training program in Immigration and Customs Enforcement. As of November 2013, the program had approved 100,000 of the 1 million foreign students in the U.S. to work for 12-31 months in a job related to their completed academic studies.