What Is a Corequisite?

A corequisite is a course that you must take at the same time as another course, or in some cases earlier. Where a prerequisite is something you must finish before a course, a corequisite is something you take alongside it. Colleges use corequisites when two courses support each other and are best learned together.

How corequisites work

The most common example is a science lecture paired with a laboratory section. The lab applies what the lecture explains, so the two are taught together and you register for both in the same term. Other pairs include a math course with a physics course, or a skills workshop attached to a gateway course.

Registration systems often enforce corequisites by requiring you to enroll in both sections before the schedule is accepted. Some institutions also use corequisite support courses, in which students who might need extra help take a college-level course together with a support class, instead of a separate remedial course first.

Why they matter

If you drop one corequisite course, you may be required to drop the other, and that can reduce your credit load below what you need for full-time status, financial aid or a visa. Failing one half of a pair may also affect your ability to continue in the sequence. Always check the department's rules before you withdraw.

Planning tips

Read the catalog description, which states whether a requirement is a prerequisite, a corequisite or either. If a course says "prerequisite or corequisite," you may take the other course earlier or at the same time. Build your timetable carefully, since the two sections must not clash.

Related terms

See prerequisite, lab section, course load and add/drop period. A corequisite is not the same as a general education requirement, which applies to your degree and not to a specific course.