By the time you're in college, life can feel like one long, endless test. Especially once you start thinking about applying to grad schools. That's when you realize that you've still got some more standardized testing headed your way. The only question is: Which tests do you need to take?

The GRE general test is probably the first test that comes to mind when you think of getting into graduate school. Just like your SAT or ACT score was probably necessary to get into college, your GRE score will assist your potential graduate programs in their admission decisions. It always helps to remember that just as your SAT or ACT score is only ONE part of your application package, your GRE score also is not the only thing the grad school program will consider.

Almost every medical school in the US and Canada will require you to send in MCAT scores. Law schools mostly require the LSAT and business schools typically request the GMAT. We say "typically" because there are now certain law schools and business schools that are also accepting GRE scores instead of LSAT or GMAT scores. (More on this below.)

Unlike with the SAT or ACT, there is not a big trend toward test-optional admissions when it comes to these critical tests of your abilities and knowledge. You will most likely have to study for at least one of these grad school tests, and you have to know your stuff.

However, an interesting development in the last several years is that more law schools are accepting the GRE instead of the LSAT. But this trend isn't only confined to law schools: Business schools are also accepting GRE scores instead of GMAT scores. Of course, it's still up to you to choose which test score to send in as part of your application at these schools — you don't have to send in a GRE score if you'd rather send in a strong LSAT or GMAT score when schools give you the option.

Here's How to Decide

Adela Penagos, president and founder of Boston-based admissions consulting firm Futuro Enlightened, points out that “some of the schools that accept the GRE instead of the LSAT or GMAT are as highly selective as others that only accept the LSAT or GMAT. Selectivity does not seem to have any direct correlation to the type of test accepted to make an admissions decision. It seems that more schools are being open as to which tests they accept."

But what about other fields of study that don't involve a profession-focused school? What if you plan to apply to a combined degree program, like an MD/JD? Do you need both the MCAT and the LSAT? Or what if you want to study for a master's in criminal justice? Should you take the LSAT or the GRE -- or both tests?

The first thing you should do is to check the program website and see what tests they require. Sure, you could always call the graduate program for clarification, but first find out if it's clearly explained online.

There's no general rule to determine which test to take when applying for a certain program. Basically, if a graduate program accepts more than one test, Penagos says it means that both of these tests are equally regarded by the school, and you should choose the test that shows your strengths.

Penagos also advises students to first take practice tests of the GRE, the LSAT (for law school applicants) or the GMAT (for business school applicants) and see which one shows off your strengths better. Which test gets you a higher score? Register to take that test and start prepping right away.

Get the Timing Right

If you do end up having to take both the GRE and another test, you should think carefully about the timing of your tests. Perhaps you're applying for a MD/PhD program and need to take both the GRE and the MCAT. Or maybe you're going for a JD/MBA, which requires an LSAT and a GMAT.

Penagos highly recommends preparing first for one test, taking that test, and only then preparing for the second test.

“It is likely that studying for one test will enable the student to develop various testing strategies and techniques that will benefit him/her when taking the second test. Therefore, I do not recommend taking the tests as far apart as possible. Nonetheless, it is important to remember that preparing for standardized tests is time-consuming, and getting ready for two tests simultaneously while still in undergrad or working full-time will be very challenging and could result in being burned out and can negatively impact performance," she explains.

If you're interested in going to grad school right after you finish your undergraduate degree, planning early is key. Penagos even suggests that students start researching grad schools and programs by the beginning of junior year. This way, you'll be able to carefully plan out your test prep strategies and you'll have enough time to prepare for every aspect of every application you submit.