If you require time off, you can apply for a Leave of Absence. To do so, fill out a Leave of Absence form. This will keep your student status active while you take a break from your coursework. When returning from a Leave of Absence, you can simply register for courses without having to reapply for the degree program. University policy allows students to leave the university for up to two semesters without needing to reapply upon returning.
For more on the Graduate College polices, visit their webpage.