Courses and Instructors → Registration Information → Prerequisites taken at U of A over Winter/Summer
As soon as you are registered for the prerequisite course at the University of Arizona for Winter or Summer, you should be able to register for the subsequent course for the following semester.
Note: The timing is important!
Summer registration usually opens at the beginning of Priority Registration for Fall (after Spring Break). You can register for your Summer course then. By the time of your Priority Registration week for Fall courses, you should already be registered for your Summer course, and can then register for the subsequent Fall course.
Winter registration usually opens AFTER Priority registration for Spring. This means that you will need to wait until Winter open registration to 1) register for the Winter prerequisite class, then 2) register for the Spring class.