<p>You don’t have your to finish in four years.
When your visa expires, you can still extend it. Even if you don’t you will still be able to take classes (but you won’t be allowed to leave the country as your visa is basically your entry permit):</p>
<p>Taken from [Student</a> Visas](<a href=“404 - Page Not Found”>404 - Page Not Found) : </p>
<p>How long may I stay on my F-1 student visa?</p>
<p>When you enter the United States on a student visa, you will usually be admitted for the duration of your student status. That means you may stay as long as you are a full time student, even if the F-1 visa in your passport expires while you are in America.</p>