<p>I'm currently signed up to take the Chemistry, Math 2, and US History Subject Tests. However, I'm going over the material and I'm realizing I'm not as well prepared as would like to be) as I would like to be for Chemistry. I'm already in AP Lit. Is it reasonable to switch to the Lit exam?</p>
<p>I believe you can switch. The weird part about the SAT subject tests is that you can switch without notifying the College Board (it’ll just grade that exam). However taking more exams than you paid for will (obviously) result in a fee.</p>