Most post-secondary programs have some type of prerequisite high school classes that you must have taken in order to register for the program. In some cases, these consist only of the regular classes you need to graduate high school. In other cases, specific programs might require an advanced grade twelve level of education in a specific science or math, such as calculus. More commonly, programs have a prerequisite average mark or grade that must be present on a high school transcript in order to gain admission.
College programs often have testing prerequisites for admission. For a basic college program, this includes an SAT or ACT score. Professional programs require advanced tests and often have a prerequisite score that must be obtained for admission. For example, law schools require an LSAT score and medical schools require the MCAT. The score prerequisites are often not fixed and instead function on a sliding scale based on the number of applicants and selectivity of admission criteria.
Some programs have specific classes that you must complete before you can register. Advanced degree programs such as medical school often have a prerequisite of this type. A medical school program usually requires that a student complete college level biology, chemistry or anatomy classes before admittance. Dental schools have similar requirements in the basic sciences.
Some degree programs ask for specific degree prerequisites for admission. Usually this applies when a person tries to get into an advanced degree program such as a master's or Ph.D. Typically students must have an undergraduate degree in the same subject, or in a closely related subject, for which they are applying to graduate school. Some schools make exceptions to this, such as when an applicant meets the requirements with an undergraduate degree in a different discipline but with relevant professional experience.