Classification of Students and Class Load

Undergraduate
Students may be classified as sophomores after earning at least 30 semester hours.
Students may be classified as juniors after earning at least 60 hours.
Students may be classified as seniors after earning at least 90 hours.
A student’s class load is determined by the number of credit hours taken per term
according to the following:
Undergraduate
Full time, 12 hours or more; three-quarter time, 9–11 hours;
half time, 6–8 hours; and less than half time, 5 hours or less
Undergraduates may not register for more than 18 semester hours. Any exception
must be approved by the academic advisor and dean of the college of the student’s
major or the University College (for undeclared majors) before registration.

https://www.mtsu.edu/advising/faqs/