• 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

  • KOS Implements New Company Policy - KOS has developed a Personnel Committee whose primary goal is to discuss personnel-related issues, policies and procedures and other performance and talent management issues with the goal of making KOS the best possible workplace. - First order of business has been to recognize changing workplace trends in the industry and create a more comfortable and enjoyable workplace. All employees working... More →
  • How to get Ready for Tax Filing - Seven Steps of Preparation - Now that the holidays are over, another event that is looming on the horizon may not be a cause for celebration: filing your tax return. Nevertheless, you can relieve some of the stress by having your return professionally prepared. There still is a little “work” required on your part, but it should not take much time or effort. Here are seven steps to guide you... 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 →
  • Congress Renews Tax Breaks in Year-End Legislation - The Protecting Americans from Tax Hikes Act of 2015 was signed into law on December 18, 2015. The law renews a long list of tax breaks known as “extenders” that have been expiring on an annual basis. This legislation makes some of the rules effective through December 31, 2016. Others are effective through 2019, and some are effective permanently. Provisions in the Act also make changes to... More →
  • Gambling with the IRS - Larry Krupp, KOS Director - lkrupp@koscpa.com - Ok, so you didn’t win the $1.5 billion Powerball jackpot. However, you should keep that losing ticket because it still may have some value. Here is a brief explanation of what to do with your losing tickets (and winnings) at tax time. - Both cash and non-cash winnings from gambling activities are fully taxable and must be reported as income. The... More →
"[KOS is] friendly, approachable, and always willing to help me find the answer to a question." - Joan Meyer La James International College