Tuition-assistance standards just got tougher. Undergraduates who fail to earn at least a C minus and graduate students who fail to earn at least a B minus would have to repay the money they receive – or forfeit it altogether – under new guidelines for the program. Also, the services no longer will cover laboratory and course fees. Other new guidelines affect compensation for taking classes with accredited post-secondary schools that have not signed letters of instruction with the services. Students who wish to use tuition assistance to pay for coursework at these non-letter-of-intention institutions must request the benefit the day classes start, rather than seven days afterward. The new guidelines take effect Sept. 5. Service members who wish to take advantage of tuition assistance in fiscal year 2014, which ends Sept. 30, have until Sept. 20 to file their requests.