Prerequisites are courses that must be successfully completed (as determined by the regulations of the department in which the course is taught) before a specific course is begun. These courses generally are part of a sequence that a department determines must be completed for the integrity of the discipline and the benefit of the student. Individual departments may set higher standards of acceptable completion of prerequisites in order to progress to the next level of the major.

Corequisite courses must be successfully completed either before a specific course is begun or at the same time as a designated course. If a corequisite has not previously been completed successfully, the student must register for both the designated course and the corequisite at the same time. In most cases, withdrawal from the corequisite may result in the need to withdraw from the primary course. Students may occasionally (after consulting their academic advisor) wish to withdraw from a corequisite course in mid-semester while remaining in the other course. This can only be done with the agreement of the instructor of the course in which the student wishes to remain. It is recommended in such a case that the student continue to audit the corequisite course while attending the other, and that the corequisite be completed during the next semester in which the course is offered.

In some departments, courses are listed as prerequisite and co-requisite to more than one course. In this instance, students may withdraw from a course but must successfully complete it prior to beginning the higher level course for which it is a prerequisite.