Maner Costerisan, a Regional Leader based in Lansing, Michigan, is expanding its presence in the western part of the state by adding Baker Holtz, based in Grand Rapids, effective Jan. 1, 2026.
The two firms signed a merger agreement in late October as part of Maner Costerisan's five year plan for growth across West Michigan.
Maner Costerisan opened its existing office in Grand Rapids office back in 2019, but it's currently in the process of expanding to a 15,000-square-foot suite to support its current team members, welcome new colleagues from Baker Holtz, and provide room for continued growth. For now, the Baker Holtz team will be staying in their current downtown Grand Rapids office throughout the 2026 tax season before they move to Maner Costerian's expanded office next spring.
"This merger is an exciting and strategic step forward for both of our firms," said Maner Costerisan president Trey Williams in a statement last week. "We've been intentional about expanding in the Grand Rapids market through internal growth and now through acquisition. Partnering with Baker Holtz allows us to bring even greater access and resources to our clients — while continuing to foster the people-first culture that defines who we are."
Financial terms of the deal were not disclosed. Maner Costerisan ranked No. 20 on Accounting Today's 2025 list of the
"Joining forces with Maner Costerisan gives our clients access to expanded resources and additional expertise, without sacrificing the personal relationships and attention they've come to expect," said Baker Holtz managing partners Ryan Holtz in a statement. "Both firms share the same values and dedication to our people, our team and West Michigan."
At the beginning of 2023, Maner Costerisan merged in
