The program end date listed on line 5 of your form I-20 is the last day you are eligible to pursue your program of study. This date is determined by the university estimate of how long your particular program should take.
Programs may be extended for legitimate academic or medical reasons. You must file for an extension with the International Student Advisor before the end date listed on your form I-20.
To apply for an extension, you will need to complete a Request for Extension of Program form with your academic advisor and submit that to the International Student Advisor. You will also need to provide current financial support documentation.