The completion date on your I-20 or DS-2019 is an estimate. If you will not complete your program objectives by that date, you must request an extension. USCIS requires that your I-20 or DS-2019 remain valid during your entire course of study.
You may be eligible for an extension if your I-20 or DS-2019 has not yet expired and you have been maintaining a lawful F-1 or J-1 status. If the delay in completing your program of study was caused by compelling academic or medical reasons, please work with your academic advisor to complete the Extension Request form at least one week before your program end date and submit to the Kearney Center.