From academic years 2003-04 through 2008-09, enrollment in WCPSS grew by more than 26%, from 108,970 to 137,607 students. Such unprecedented enrollment growth presented challenges for the Wake County Public School System (WCPSS). Enrollment outpaced new school construction and led to overcrowding. In addition to constructing mobile classrooms, the district began to operate overcrowded schools on the multi-track year-round (MTYR) calendar. Unlike the traditional calendar in which students have a summer break, schools on the MTYR calendar operate throughout the calendar year including the summer months. Enrollment in WCPSS continued to climb during the next decade and peaked at nearly 162,000 students in the 2019-20 academic year. Enrollment followed national trends and fell following the COVID-19 pandemic but appears to be rebounding as evidenced by the enrollment growth of about 1,600 students between 2022-23 and 2023-24. Although overall district enrollment has stabilized, enrollment patterns across schools have been uneven in recent years. Some schools have experienced overutilization, where enrollment exceeds capacity, while others face underutilization, with capacity exceeding enrollment. The previously reported trends present ongoing challenges for student assignment in WCPSS, raising questions about facility utilization and costs associated with the MTYR calendar. Student outcomes are also increasingly relevant, particularly in understanding how student achievement may vary by calendar type. As such, the use of the MTYR calendar warrants close examination. This study examines the use of the MTYR calendar in WCPSS and addresses the following questions: (1) What is the history and current state of MTYR calendar use in WCPSS? (2) What are the relevant crowding and cost considerations? (3) To what extent, if at all, does the MTYR calendar affect student achievement? [This project was completed through a research-practice partnership involving the WCPSS Office of School Choice, Planning, and Assignment; the WCPSS Data, Research, and Accountability Department; and Elon University, Martha & Spencer Love School of Business.]