Our Team

Clayton Stiffler


CPA, CCIFP, Senior Manager

Small & Midsize Businesses
DEPARTMENT: Accounting

Clayton Stiffler, CPA, CCIFP, Senior Manager

Clayton joined Maner Costerisan as an associate in 2014. His strong work ethic and passion for problem-solving drove his quick progression through firm ranks, being promoted to senior manager in 2021. In his role, he provides accounting and outsourced expertise to a variety of clients, including small and midsize businesses. He recently took a leadership role overseeing the firm’s Construction specialty and earned the Certified Construction Industry Financial Professional designation.

An active member of Maner’s Employee Engagement Committee, Clayton is deeply committed to making Maner a great place to work. He helps the team plan and execute activities focused on driving engagement across the staff. Prior to joining Maner, Clayton worked at BS&A Software, gaining experience on its Financial Management support team.

Clayton enjoys getting to know his clients and taking an active role in helping them grow their businesses. He credits his success at Maner to focusing first on the success of his clients. He lives by the mantra that their success leads to his.

Clayton graduated from Michigan State University with both a Master of Science degree and Bachelor of Science degree in Accounting. While in college, he was on the Dean’s List for eight semesters.

A traveler at heart, Clayton’s visited all the lower 48 states and hopes to visit the last two in the next few years. A resident of East Lansing, Michigan, Clayton enjoys frequenting Michigan State athletic events with friends.

Every day at Maner is different than the one before. I thoroughly enjoy being "kept on my toes.”

Years of Experience



American Institute of Certified Public Accountants (AICPA)

Michigan Association of Certified Public Accountants (MICPA)

Construction Financial Managers Association – Lansing (CFMA)


Certified Public Accountant (CPA)

Certified Construction Industry Financial Professional (CCIFP)

QuickBooks Certified ProAdvisor