Our Team

Trey Williams


CPA, Principal, Director, President

Employee Benefit Plans

Trey Williams, CPA, Principal, Director, President

Trey is the president of Maner Costerisan, guiding the firm’s strategy, overseeing daily operations, and working to grow the firm’s profitability and services. He is an active and longtime member of Maner’s Construction team and leads peer review services.

In addition to his leadership roles, Trey’s day-to-day responsibilities lie in providing services to nonprofit associations and small businesses in the construction and service industries. He also works with organizations in the ERISA industry.

Since his career began, Trey has helped numerous clients overcome obstacles and address critical issues regarding their businesses. He shares his expertise with organizations outside of his clientele, presenting for the Michigan Association of Certified Public Accountants, Central Michigan Chapter of ABC and publishing articles for The Greater Lansing Business Monthly magazine.

Trey’s decision to pursue a career in accounting was the result of his being raised in a family-owned business, which helped him gain experience and shape his perspective on a number of business related issues. His success today is a result of his overall enjoyment of the profession, including the people he works with and the clients he serves.

Trey resides in Grand Ledge, Michigan with his wife and three children. In his free time, he enjoys spending time with his family, fishing, camping, playing golf and collecting coins. He is also an avid Michigan State University Spartans sports fan.

I strive to act with a sense of urgency when handling my clients’ issues. I understand people don’t like to be kept waiting for answers and therefore I work hard to always be available and responsive. In today’s fast-paced world, it is important to respond to clients in a timely manner so information remains fresh in their minds.

Years of Experience



American Institute of Certified Public Accountants (AICPA)

Michigan Association of Certified Public Accountants (MICPA)

Construction Financial Managers Association (CFMA), Former Treasurer

Associated Builders and Contractors (ABC)

Associated General Contractors of America (AGC)

Old News Boys, Former President

Rotary Club of Lansing


Certified Public Accountant (CPA)

AICPA Advanced Defined Contribution Certification