<p>Regarding SAT Subject Test requirements, this link has a well-maintained compilation of them (click on the school’s name for more detail and a link to the relevant web page).</p>
<p>[Compass:</a> Admissions Requirements](<a href=“SAT Subject Test Requirements and Recommendations - Compass Education Group”>SAT Subject Test Requirements and Recommendations - Compass Education Group)</p>
<p>No school requires three for general admission any longer (I think Princeton was the last), although you can see from the link that both Georgetown and Johns Hopkins recommend three. Some special programs, such as Northwestern ISP, still require three. Home schooled students might also be asked to provide more than the general requirements call for.</p>