Firm History

1968

Alfred E. Mueller, CPA, a Partner with Hughes, Mueller and Company located in Elgin decided to branch out and start his own firm.
Ed Sieracki, CPA, a Staff Accountant from Hughes, Mueller and Company was interested in joining Al on his new endeavor and the two opened a new firm, Mueller, Sieracki & Company. They started operations on October 1, 1968 with Al Mueller as the Managing Partner.
Bill Kaun, CPA, a former employee of Hughes Mueller and Company, decided to re-join Al and Ed in the public accounting arena and the firm became Mueller, Sieracki & Kaun.

With the addition of several larger clients the firm began to flourish. This led to the need to departmentalize and increase staff. During the early 1970’s the firm instituted an audit department and a tax department.
The firm acquired the bookkeeping practice of Eugene Uttenweiler in September of 1973.
In 1974 Glenn Miller, CPA became a Partner and in 1978 the firm's name was changed to Mueller, Sieracki, Kaun, Miller & Co.
Kleeman, Brooks & Co., a St. Charles based firm, merged with Mueller, Sieracki, Kaun, Miller & Co. in 1979. The firm now had two office locations and Robert E. Kleeman, CPA and Doug Brooks, CPA became Partners. That same year, Dwain K.Tataryn, CPA, CFP® and Robert G. Turner, CPA became Partners and Ed Sieracki, CPA became the Partner-In-Charge of the St. Charles office.

The firm shortened its name to Mueller & Co. in 1985.
Bill Kaun, CPA became the new Managing Partner and Mike Stephens became a Partner in 1986.
In 1989 David J. Nissen, CPA, CVA, became a Partner of the firm and took over the reins of management at the St. Charles office.

Glenn Miller became Managing Partner and Dwain Tataryn took over the financial planning portion of the practice, known as Mueller Financial Services in 1990.
Mueller Financial Services was incorporated in 1992 and the entity name changed to Mueller Financial Services, Inc.
In 1997 the firm registered with the State of Illinois as a Limited Liability Partnership and became Mueller & Co., LLP.
Gary E, Kemnitz, CPA, CFE became a Partner in 1998.
In the beginning of 1999 Dwain Tataryn became Managing Partner of the firm and in June Roy W. Groesbeck, CPA and Randall J. Rupp, CPA joined the firm as Partners.

In 2001 James J. Hare, CPA and Beth W. Wright, CPA, CVA became Partners.
Mueller & Co., LLP merged with the Willowbrook based firm Bradley & Company CPAs, P.C. in 2002. Arthur T. Bradley, Jr., CPA became a Partner of Mueller & Co., LLP and Precision Payroll of America, LLC became part of the Mueller family of companies as a result of this merger.
Since its inception, Mueller & Co. has provided business consulting services to clients. In 2003 Mueller Consulting, LLC was formalized as its own entity under Mueller & Co., LLP.
Brian Sullivan, CPA became a Partner in 2004.
Tom Sodeika became Managing Partner of Precision Payroll of America, LLC.
In the fall of 2004, the Elgin office relocated to new premises at Point Boulevard, Elgin.

Jeffrey A. Delheimer, CPA, who started with the firm in 1997, became the 13th Partner.
January, 2006 - The Mueller Companies merged with the Aurora based firm Nickels, Beilman & Co., P.C. Michael E. Beilman, CPA, ABV, CVA, CCIM joined the company as Partner and the firm gained eight additional staff members. The union expanded Mueller’s expertise in business valuations and litigation support.
May, 2006 - After 19 years in Willowbrook, Mueller & Co., LLP and Precision Payroll of America, LLC relocated to new premises in Oakbrook Terrace, IL. The continued annual growth of the company necessitated finding new premises to accommodate additional staff. The firm now has over 80 employees with offices in Elgin, St. Charles and Oakbrook Terrace.
May, 2006 - Dave Nissen was elected as Managing Partner of The Mueller Companies. He has responsibility for further developing the extensive services provided by all of The Mueller Companies.

Mueller & Co., LLP celebrates its 40th Anniversary. At this point in our history, we have 13 partners and over 100 employees located in 3 offices.