Mark has been married to Shannon for 29 years. She is an elementary school teacher in Arlington Heights. They have three children, Matthew (25) is a mechanical engineer, Kaitlin (23) is an elementary school teacher, and Christopher (19) is a mechanical engineering student. All his children attended Cary schools and graduated from Cary Grove High School. They enjoy a number of activities with family and friends, including boating and water sports on local waterways, snow skiing, and cheering on local sports teams.