Our Team


CPA, Principal


Mark Lockwitz, CPA, Principal

With over 20 years of experience, Mark specializes in providing audit, assurance and consulting support to Maner Costerisan’s nonprofit clients. A principal in the firm’s Audit department, Mark also serves as the firm’s Continuing Education Director and monitors the continuing development and education of the firm’s greatest resource, its people.

With his extensive background and specialization in the nonprofit arena, Mark is regarded as an expert in his field and is well-respected by his peers. Mark is also involved with organizations that require single audits as a result of requirements set forth by the OMB Uniform Guidance due to federal funding received. He regularly shares his knowledge with others throughout the accounting and nonprofit communities, often serving as a speaker.

A transplant from Southeast Michigan, Mark moved to Lansing shortly after graduating college. While the firm’s central location is what initially piqued his interest in Maner, it was the people who sealed the deal. To this day, he credits the firm’s people and unique culture as the reason he’s stayed for more than two decades.

Like many CPAs, Mark was good at numbers from a young age. But what drew him to the industry was the opportunity to learn and interact with people from various organizations and backgrounds. Helping people reach their goals is what keeps him interested, engaged and learning.

An avid supporter of animals, Mark has served on the Board of the Capital Area Humane Society, often as the Board Treasurer. A fan of movies, playing games and enjoying time outdoors, Mark and his wife live in Grand Ledge, Michigan, with their three children and three dogs.

In my personal life and professionally, I have always gravitated towards a quote from Spencer Johnson...

"Integrity is telling myself the truth. And honesty is telling the truth to other people."

In our profession, integrity is all we have and our clients rely on us to share the truth we have to offer.

Years of Experience



American Institute of Certified Public Accountants (AICPA)

Michigan Association of Certified Public Accountants (MICPA)

Nonprofit Task Force Capital Area Humane Society, Board Member


Certified Public Accountant (CPA)