Our Team

Diana Mitchell


CPA, Senior Manager


Diana Mitchell, CPA, Senior Manager

Diana joined Maner Costerisan in 2013. As a senior manager, she provides tax compliance, tax planning, and business advisory services for both individual and business clients, with a specialty in services related to fiduciary accounting, trust and estate planning, and trust and estate tax compliance. In addition to her client responsibilities, Diana is involved with internal training and is a member of the firm tax department’s strategic planning and tax training teams.

With over 23 years of professional experience, Diana has a broad range of business experience, which allows her to advise clients on a variety of issues and transactions they may encounter when making financial and business decisions. In particular, on more than one occasion, she has assisted families with relatives who passed and helped guide them through all the required accounting, tax return filings, and asset distributions matters.

Diana attributes much of her success to interpersonal skills and attention to detail. As a young person, she thought accounting would be a set of skills that would always provide a way to support herself. After Diana got into accounting, she enjoyed the puzzle solving aspect and helping others with understanding how it all works. At her first job as a bookkeeper during college, she had a great mentor. Her mentor’s love for accounting was also a factor in her pursuing a career in accounting.

Diana grew up in Grand Ledge, Michigan and now calls Haslett her home. She spends her time away from the office with her two sons and her husband, Josh. Outside of the office, Diana enjoys volleyball, reading and gardening. She is also an active “crossfitter” and even completed the Warrior Dash Race twice in the past two years, beating her last finish time by 15 minutes.

I want to provide the best service I can to my clients by not only doing quality work, but also by being a person they can have confidence in and rely upon as a trusted advisor.

Years of Experience



American Institute of Certified Public Accountants (AICPA)

Michigan Association of Certified Public Accountants (MICPA)

Greater Lansing Estate Planning Council (GLEPC), Board Member

Michigan State University Alumni Association


Certified Public Accountant (CPA)

Certified Specialist in Estate Planning (CSEP)