• Welcome to KOS!

    With an over 80-year history, the mid-sized accounting firm of Kessler Orlean Silver & Co., P.C., provides innovative accounting solutions to business owners, executives and managers, private investors, and professionals.

    Our down-to-earth style and practical experience come from a long-time culture of helping people and feeling passionate about doing so!

  • What Sets Us Apart

    We care. Pure and simple.

    ‘Above and beyond’ dedication to client service is our highest priority. Clients tell us they appreciate our accessibility and outstanding service. We believe it’s essential that you receive our close personal attention with prompt answers and new ideas.

    No situation is too tough or too routine. Every challenge is viewed with a fresh eye and resolved with a creative solution.

    By placing our service standards front and center in the way we conduct business, you can expect to receive the highest quality service while we help you improve your business or personal financials.

  • On the surface, accounting firms seem a lot alike. But some stand out from the crowd. So what makes KOS different? Our people. Sincerely caring, really listening, and then putting your outcome ahead of our interests. It’s our exuberant: to put you above all else.


    Based in Deerfield, a Chicago suburb, KOS serves businesses and individuals in multiple states providing business consulting, accounting and bookkeeping, and tax services.

Firm Profile

Learn more about the firm’s people, philosophies, and client service commitment.


Our monthly newsletter is available online and keeps you current on tax and financial matters.

KOS News Ticker

  • Introduction to the New Credit Cards - Changes for businesses in the works - Credit card issuers are continuing to roll out new cards designed to deter identity (ID) theft. That is good news for consumers who might otherwise be victimized by thieves stealing their personal information. However, the responsibility for losses resulting from ID theft has also shifted, resulting in changes for business entities of all shapes and sizes. -... More →
  • Tax Notices - Bruce Kreisman, Tax Supervisor bkreisman@koscpa.com - Receiving a tax notice from the IRS or a state department of revenue may not be what you were hoping for in the day’s mail. But in many cases the notice can be resolved both quickly and painlessly. - A taxing authority such as the IRS or the Illinois Department of Revenue will issue a written notice under various scenarios, some of which are... More →
  • KOS is Hiring! - KOS is a place where you can build a career that incorporates interesting assignments, training for new skill sets, a great company culture, and a reasonable balance between working and down-time. - Our firm is currently seeking talented, entrepreneurial-minded, advancement-oriented individuals for the following openings: Staff Accountant and Accounting & Auditing Senior/Supervisor. We are... More →
  • Tips for Teaching Kids about Money Management - Diana Spatoulas, Senior Accountant dspatoulas@koscpa.com - By now our kids are well into the school year taking part in daily classroom activities. Whether they are learning their A-B-C’s or studying advanced calculus, as parents it is up to us to teach our kids one of life’s many great lessons: money management. We are the primary influence on our kids’ financial behaviors. Teaching them... More →
  • Five Ways to Avoid 100% Penalty - Corporate officers may be personally liable - Frequently, someone in your company—it may be the president, vice president, treasurer or some other officer—will have assumed the duty of collecting and depositing federal payroll taxes. That person could be in for a rude awakening one day. - According to an onerous provision in the federal tax law, any person who willfully fails to deposit the... More →
"[KOS is] friendly, approachable, and always willing to help me find the answer to a question." - Joan Meyer La James International College