Timothy D. Umbreit, CPA, CGMA
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Bonnie W. Korengel, CPA
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Kathleen A. Wileczek, CPA
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The Partners

Each of our partners is trained and qualified to handle the entire spectrum of Umbreit Korengel & Associates financial services, yet each specialize in particular areas of interest. We work as a team, combining our expertise to ensure that every decision is optimal…regardless of current economic conditions or immediate challenges in your industry.


Timothy Umbreit Timothy D. Umbreit, CPA, CGMA
Tim Umbreit formed Timothy D. Umbreit, P.C. in 1984. The firm expanded in 1994 adding a partner and changing the company name to Umbreit, Korengel & Associates P.C., clearly indicating the new association with Bonnie Korengel.

After graduating with a BS in accounting from Clarion University in northwestern Pennsylvania, Tim received his CPA certification in 1982. He gained experience with a large Wilmington, Delaware, CPA firm and formed his independent practice shortly afterward. His strong credentials have developed from serving a network of private industry clients representing a full complement of businesses. These customers have required an extensive array of accounting functions. Tim recently earned his designation as a chartered global management accountant.

A native of Chester County, Tim chose the accounting field because of its ever-present challenges and diversity as well as the constant demand created by changing tax laws. He is a member of the American Institute of Certified Public Accountants, the Pennsylvania Institute of Certified Public Accountants, and the Delaware Society of Certified Public Accountants.

Tim has been active in various organizations, including the Kennett Park and Recreation Board (president and treasurer), Kennett Consolidated School Board of Education (treasurer), Kennett Square Lions Club, Kennett Symphony Orchestra Board of Directors (president and treasurer), Symphony Endowment Fund (treasurer) and the Kennett Ice Hockey Club (president).
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Bonnie Korengel Bonnie W. Korengel, CPA
Bonnie Korengel, one of Umbreit, Korengel & Associates principals, merged her strong financial skills with those of managing partner Tim Umbreit in 1994 to form Umbreit Korengel & Associates P.C.

After graduating from Bradley University in Peoria, Illinois, Bonnie received her Master’s degree from Illinois State University. She became a certified public accountant in 1992. Bonnie is experienced in all aspects of financial management and specializes particularly in nonprofit organizations. She is a member of the American Institute of Certified Public Accountants, the Pennsylvania Institute of Certified Public Accountants, and the Delaware Society of Certified Public Accountants.

As a longtime southern Chester County resident, Bonnie stays active in a variety of community organizations, which include Rotary International, the Kennett Education Foundation (Board of Directors), and Brandywine Battlefield Park Associates (Board of Directors). She also provides financial oversight for the Chester County League of Women Voters and serves as a guide at Winterthur Museum in Wilmington, Delaware.
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Kathleen Wileczek Kathleen A. Wileczek, CPA
Kathy is a recent addition to the team at Umbreit Korengel & Associates, P.C. She received her Bachelor of Science in Accounting from St. Joseph's University and has over twenty-five years in the practice of public accounting. Her expertise includes extensive work with clients in manufacturing, construction, real estate, technology, professional services and not-for-profit entities. She works with business owners and executive directors to develop and support accounting and financial needs.

As a long-term West Chester resident, Kathy is actively involved in business and community events and the support of local non-profits. She is an active member of the Greater West Chester Chamber of Commerce and currently serves as Secretary to the West Chester Business Improvement District and on the March of Dimes Chester County Women of Achievement committee.
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