Non-matriculated students are those who have not yet been formally admitted to a degree program. They are usually students who are new to a graduate program and who have not yet decided officially to pursue an advanced degree. The non-matriculated status allows a new student to become familiar with the university—the faculty, the other students and the curriculum—before deciding to pursue a degree.
You can take a maximum of nine (9) semester hours of courses for credit without officially enrolling in the MSEd program (i.e., when you are a non-matriculated student). If you try to register for any further courses (i.e., either a fourth course or your tenth graduate credit) as a non-matriculated student, your registration will be blocked. For this reason, it is important that you begin the matriculation process while taking your third course, as this will ensure that you are not blocked from taking a (fourth, fifth, etc.) course that you are hoping to enroll in.
Normally, courses taken prior to matriculation can generally be counted towards your degree if they have been taken within the previous three years.