The Service issued an interim memorandum clarifying the requirements for 17 months extension for post completion Option Practical Training for STEM students. F1 students are usually eligible for 12 months of Optional Practical Training to gain practical experience in the United States after they complete their course of study. F1 students are also eligible to work off-site, under Curricular Practical Training, during their course of study if they receive authorization from the Service and their institutions. STEM students are eligible for 17 additional months of Practical Training. The proposed rule makes STEM students eligible for the extension even if they have not finished their STEM thesis. The comment period ends on November 1, 2013.