Joe Schilz, CPA

Joe has spent his entire professional career in the accounting business, establishing his practice in 1987 after working for four years as an auditor for the Wisconsin Department of Revenue.

Joe is a Muskego native and high school graduate, and earned his Bachelor of Business Administration from UW-Whitewater in 1983, with a major in Accounting. Joe and his wife Jackie have three daughters, Gina, Abby, and Josie.


Brian Dziak, CPA

Brian is long-time team member, joining us in 1993 after earning his Bachelor of Science in Accountancy from Marquette University in 1991.

Brian is a business expert, specializing in management consulting and tax planning for small-to-medium sized companies. He has over fifteen years’ experience working with and consulting to privately-held companies and S-corporations, typically performing vital services like reviewing financial statements and performing tax planning and preparation.


Mike Murphy, CPA

Mike has over 25 years of business operations and accounting experience. He graduated from UW-Whitewater with a BBA in Accounting.  He received his MBA from UW-Milwaukee.

Mike and his wife Judi reside in Brookfield. They have two grown children; Jake is also a CPA, and Kelli is a social worker. Mike and Judi enjoy sports, travel, projects around the house, and time spent with friends and family.

Don't Be Shy. Get In Touch.

If you are interested in working together, send us an inquiry and we will get back to you as soon as we can!

Contact Us

Nick Johnson

Nick specializes in individual and business tax preparation at Joseph A. Schilz, S.C.  He graduated from UW-Whitewater with a Bachelor of Business Administration (B.B.A.) in Accounting and earned his Master of Business Administration (M.B.A.) from UW-Parkside.

Nick is also a fully licensed Financial Advisor. He works with business owners to establish employer sponsored retirement plans, along with individuals looking to plan for their financial future, and those thinking about retirement. He finds that tax planning and financial planning hold an important relationship with one another.

Nick enjoys spending time with his wife and young daughter. Whether it’s trying new restaurants, wandering off on spontaneous road trips, or checking things off the bucket list, Nick and his family are always on the go!


Tammy Kersten, EA

Tammy joined the Joseph A. Schilz, SC team in 1997, after earning a Bachelor of Business Administration with a major in Accounting from UW-Milwaukee.

In 2012, she earned the Enrolled Agent designation from the Department of the Treasury.  In addition to individual tax preparation, Tammy serves many small business accounting needs with an additional focus on QuickBooks.


Mitch Longley

Mitch is a Bookkeeper and Payroll Specialist here at Joseph A. Schilz, S.C. Graduating from MATC in 2012 with a degree in accounting he immediately jumped right into the accounting and tax profession. He enjoys learning and exploring every option that a career in accounting has to offer.

Growing up in Grafton, Mitch enjoys spending time with his wife and family. He also enjoys playing golf any chance he can get.


Janice Lien

Janice has been with the firm since 1996. Her education and background are in graphic design.

She has two daughters, both with creative talents. Brianna is an architect and Brittany has a background in art and design.

Janice enjoys arts & crafts, reading, music and dancing. She is a member of the Polish Heritage Alliance and the Bristol Friends of Faire.


Jami Koulos

The newest member of the team, Jami joined us in August of 2016. Prior to joining the firm, she worked in the insurance field, as an agent. She earned her Bachelor of Science in Accounting from Lakeland College in 2012. 

Outside of the office, Jami enjoys spending time with her family, crafting, reading, traveling and everything else life has to offer.