If a student on a F-1 visa is not able to complete their studies by the expiration date on the I-20 form, they must apply to the school’s Foreign Student Advisor for an extension 30 days before expiration. Extensions are normally granted for academic and medical reasons so long as there have been no violations of visa status.
It is possible to transfer schools after arrival on an F-1 visa. You will need to notify your current school of the transfer and obtain an I-20 form from the new school. You will complete the student certification section of the I-20 and must deliver it to the foreign student advisor at the new school within 15 days of beginning attendance at the new school.
If you are changing majors at your current school, you do not need to notify the INS. If you are changing degree programs (e.g., from a bachelors degree to a masters degree program), however, you will need to get a new I-20 and submit it to the foreign student advisor within 15 days of beginning the new program.