Michael L. Door

Certified Public Accountant licensed to practice in Michigan. A member of the national and state associations for CPA’s, Mike joined the firm in 1983 after earning degrees from Aquinas College and Davenport University with majors in accounting and business administration. He specializes in small business accounting and taxes. Mike has also completed training with the Dave Ramsey organization and is a certified budget counselor.


Steve Penning

Brings a keen knowledge of computer accounting to the firm. A Certified Public Accountant and a member of the national and state CPA associations, he joined Lettinga & Associates, LLC- CPA’s in 1989. Steve is a graduate of Calvin College with a bachelor’s degree in business with a concentration in accounting.


Douglas Keegstra

Certified Public Accountant licensed to practice in Michigan. Doug joined the firm in 1996 after 12 years in private industry as an auditor and controller. Doug holds a bachelor’s degree from Louisiana State University and masters degrees in business administration and tax from Grand Valley State University. Besides being a CPA, Doug is also certified to perform business valuations.


Dennis L. Gillett

Over twenty-five years of experience in public accounting, focusing on general accounting and preparing taxes for individuals, partnerships and corporations. Dennis graduated from Davenport University where he majored in accounting. He has been a member of the Lettinga & Associates LLC- CPA’s team since 1986. Dennis is enrolled to practice before the Internal Revenue Service and is a member of the Independent Accountants Association of Michigan.


Chris Deiss

Chris holds a bachelor’s degree in Accounting and Business Administration  from Davenport University. He has been working for Lettinga & Associates since 2011. Chris specializes in accounting software, small business accounting and taxes. In 2014 Chris became an Enrolled Agent. As an EA, Chris is licensed to represent clients before the Internal Revenue Service.


Jason Butler

Jason graduated from Grand Valley State University in 2011 with degrees in Accounting and Finance.  He has experience with both corporate and personal tax returns. A Certified Public Accountant, Jason joined Lettinga & Associates in 2013.