Northeastern has one of the largest cooperative education (co-op) programs in the world. Started in 1909, NU's co-op program is one of the oldest in the nation. In the co-op program, students alternate periods of academic study with periods of professional employment (usually paid) related to their major. Most majors offer a four-year graduation option with fewer co-op placements, but the five-year program is slightly more popular with students. Students on co-op do not pay tuition and students not living on campus do not pay room and board. The co-op program typically begins the spring of the second year or fall of the third year (after a more traditional program for the first semesters on campus). Students usually take anywhere between one and three with 96% participating in one and 78% participating in two or more.