Jansen practices in the areas of civil and real estate litigation, probate litigation, estate planning and eminent domain. He is a member of the Grand Rapids and American bar associations, State Bar of Michigan and National Order of Barristers. He is also a board member for Camp Blodgett. Jansen received his bachelor's degree in political science and international studies from Michigan State University in 1984 and his law degree from Wayne State University in 1988, where he was a member of the Philip C. Jessup International Law Moot Court team and chancellor of the Moot Court Program.