All international students on F1 (Form I20) and J1 (DS2019) are required to maintain full time student status and have certain reporting requirements.
Full time international students on student visas are limited to working on-campus with specific guidelines. International students are not authorized to work off-campus unless unless special conditions apply.
The Intensive English Program (IEP) is available for students in select countries who need additional English language study before entering their desired University major.
Your F-1 or J-1 visa (marked D/S) is only required for initial or re-entry into the US. If your student visa has expired during your studies, you will need to renew it the next time that you leave the US. Status is determined by the I-20 validity, not the visa duration.
International students must file United States federal (and usually Missouri state) income tax documents each year. The date to submit these documents is 15th of April following the year of the taxable income.