Who We Are

Cassell Plan Audits is a certified public accounting and business advisory firm primarily geared toward employee benefit plan sponsors or public accounting firms. Founded by JoAnn Cassell, a former national accounting firm professional, we provide services for those in need of technical employee benefit plan resources.

Employee benefit plan audits and related services are the sole focus of our business. It’s all we do!

If your last plan audit seemed to go on for months, or the request lists from your auditor continued weeks after the initial visit, we invite you to contact us today. Our streamlined approach, based on decades of experience and leveraging technology, allows us to provide you with an audit experience that is efficient, affordable and minimally disruptive to your business. We save you time and make the unavoidable audit process as painless as possible.

JoAnn Cassell

joann cassell plan audits

CEO and founder of Cassell Plan Audits, Inc., a specialty accounting firm located in Chicago’s western suburbs and serving clients in all 50 states, JoAnn brings 30 years of public accounting experience and 20+ years specializing in qualified plan audits.

Her memberships and affiliations include:

  • American Institute of Certified Public Accountants (AICPA), and member of its Employee Benefit Plan Audit Quality Center
  • Illinois CPA Society (ICPAS), member of its Employee Benefit Task Force, and Employee Benefit Plan Conferences Planning Committee
  • American Society of Pension Professionals and Actuaries (ASPPA) with a designation of Qualified 401(k) Administrator (QKA), serving as the Trustee of its Benefits Council, Chicago (ABC) and as its former President and VP of the Membership Committee.

AICPA certificates Cassell

JoAnn lives in St. Charles with her family. When not in the office, she travels, runs marathons and spends time on the water.

JoAnn has cultivated a well-deserved reputation as the “friendly auditor.” She’s on your side, helping you find solutions, rather than simply identify compliance issues. And, she’s built a team of friendly auditors to assist:

Kimberly R. Townsend

Kim earned a Bachelor of Science degree from Madonna University in 2005. Then, after working as a corporate financial consultant for four years, returned to school to focus on accounting and earned a second degree in business administration with a concentration in accounting from Baker College in 2012.

Prior to joining Cassell Plan Audits in 2021 as an auditor, Kim worked in corporate accounting for close to a decade acquiring a broad range of financial skills and accounting experience, including auditing employee benefit plans. Throughout her career, her goal has been to help employers achieve successful growth. At Cassell Plan Audits, she brings her advanced accounting skills to audits of financial statements and works directly with clients during the auditing process helping to ensure their needs are met.

Kim lives in Plymouth, Michigan with her husband and two sons. Outside of work, she enjoys yoga, traveling, and cooking–with a specialty in authentic Neapolitan pizza. 


Jennifer Pettis

Jennifer holds a master’s degree in Accountancy from the University of Illinois at Urbana-Champaign and is a registered CPA in the State of Illinois. She joined Cassell Plan Audits in 2014 with 3+ years of public accounting experience specializing in qualified plan audits. She is passionate about working with clients to find creative and workable solutions to compliance issues.

Jennifer lives in Wheeling with her husband, and enjoys reading, playing cards and exploring new places.



Anne Kozlowski

Anne received her bachelor’s degree in Accountancy from Elmhurst College and is a registered CPA in the State of Illinois. She brings 20+ years of experience  as an auditor, accountant, and tax professional in public accounting, working with corporations and nonprofits in many industries. She is certified by the American Institute of CPAs in both Intermediate Employee Benefit Plans Audit and Advanced Defined Contribution Plans Audit.

A long-time advocate for clients throughout Illinois, she assists with budgets, cash flow, forecasting, and audits, including specialized audits of employee 401(k), pension, health and welfare, and ESOP plans. She lives in the Chicago area with her husband, two boys, dog, and cat.


Kaisa Davis

Kaisa has a background that includes 10+ years’ experience in accounting, audits, and internal controls. She brings cross-industry expertise gained as a senior auditor for a public accounting firm, as well as on staff at a publicly traded firm and multiple manufacturers. She studied at Northern Illinois University and serves clients throughout the country. When she’s not at work with us, she’s at home cuddling her dog and two cats.





Jen Williamson

Jen earned her bachelor’s degree in Accounting at the Gies College of Business, University of Illinois Urbana-Champaign. She brings 25+ years of experience as an auditor and quality control specialist working across diverse industries, as well as manager and trainer to other auditors.

An expert in accounting and audit standards, Jen has a passion and real knack for the technical research required to resolve the most complex regulatory and financial issues. As an auditor at Cassell Plan Audits, she looks forward to concentrating on this area of her expertise.

Jen lives in the Greater Chicago Area with her partner, two sons, and a Schnoodle (poodle-schnauzer mix) named Cooper.



Judy Trader

Judy joins us part-time every year to handle light accounting and administrative tasks, so the team can better focus on completing plan audits during our busiest season. She brings 20 years of office management experience to the job and makes everyone’s life easier so we can better serve our clients. She’s a dog lover and happens to be Jennifer Pettis’s mom.


Stella is the resident Office Dog Extraordinaire. A golden doodle now two years old, Stella visits the office nearly every day to offer affection, accept head scratches and keep office morale high. Our office wouldn’t be the same without her.