The STEM Extension allows F-1 students who have received a degree in specific fields in science, technology, engineering, or mathematics, to apply for an extension of their regular OPT period (maximum: two STEM OPT periods per lifetime). The STEM OPT extension is a 24-month period of temporary training that directly relates to an F-1 student's program of study in an approved STEM field as listed above. Students may not apply for STEM OPT extensions during the 60-day grace period following an initial period of regular post-completion OPT.