Our Team

Robert J Wiersema III, Manager

Robert Wiersema III joined Maner Costerisan in July 2026 as a manager, bringing nine years of experience in school business and accounting, including six years in management. Before joining Maner, he served as a Finance Director for a school district, where he prepared and presented budgets and monthly financial statements to the Board of Education and oversaw the daily operations of the business office. In his current role at Maner, Robert provides multifaceted support to school district clients and works with school business official organizations to promote best practices across the field. He also holds a Chief Financial Officer (CFO) Certification from the Michigan School Business Officials.

Throughout his career, Robert has been driven by a love of problem-solving and a desire to bring order to complex situations. His interest in numbers and rules led him to school business and accounting, where he enjoys helping others find solutions and takes pride in work done well. He values the opportunity to build relationships with clients and support the important work of school districts. Robert serves as Treasurer and Past President of the Southwestern Michigan School Business Officials.

Robert earned a Bachelor of Science in Accounting from Colorado State University Global and a Master of Professional Accountancy from the University of South Dakota Beacom School of Business, graduating magna cum laude with his undergraduate degree. He lives in Portage, Michigan, with his wife, Katie, their two children, James and William, and their cat, Miso. Outside of work, Robert enjoys playing board games and tabletop role-playing games, where he often takes on the role of explaining the rules and teaching others how to play.

“I love getting to help people solve problems! Nothing is more satisfying than a job done well and correctly.”