Mark Michelini became the third business manager in Stevenson High School's history in 2005, following Jim Hintz and Edward Ellis. Michelini has had many roles in his 28 years in education. He began his career as an accounting instructor at the University of Wisconsin-River Falls. After four years in education and upon completing his MBA and passing the CPA exam, Michelini left teaching for a position with an accounting firm in his hometown of Aurora. While in Aurora and pursuing a certified School Business Official degree at Northern Illinois University in 1993, he joined Stevenson.