• 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 Introduces KOS Financial Services - PRESS RELEASE - FOR IMMEDIATE RELEASE - August 17, 2016 - KOS Introduces KOS Financial Services - The CPA firm of KOS has a financial advisory division headed by Tony Gacs - Kessler Orlean Silver & Co., P.C. (KOS) is pleased to announce that Tony Gacs has joined the firm to head its’ new division KOS Financial Services. As a financial advisor, Tony adds to KOS’ ability to serve businesses... More →
  • Giving the “Right Stock” to Charity - Tax rules may affect your donations - Do you own shares of stock that you want to contribute to charity? Before you pull the trigger on the donation, make sure that you give away the “right kind” of securities instead of the “wrong kind.” It can make a big difference on your tax return. - The conventional wisdom is to donate low-basis stock you’ve held for a long time. That way, you can... More →
  • What’s Your Small Business Worth? - How to value business interests - It is often difficult to put a price tag on a company that is not publicly traded. For instance, the value of a family-owned business will typically exceed the total value of the hard assets such as equipment and inventory. In addition, assigning a value to intangible assets such as goodwill is a difficult proposition at best. - Frequently, it makes sense to have... More →
  • Facts and Figures - Timely points of particular interest - New IRS Due Dates for 2016 Returns - We wanted to let you know that the IRS has changed the due date of certain tax returns effective for 2016 tax returns. The biggest impact will be on the forms W-2 and 1099 MISC. They are due to the SSA/IRS one month earlier than before. - Form W-2 – due to the SSA on January 31st – the old due date was February 28th -... More →
  • The Painful Truth about the Alternative Minimum Tax - Diana Spatoulas, KOS Senior Accountant - dspatoulas@koscpa.com - Most people have never heard of the alternative minimum tax (AMT), and those that have probably would love to forget about it and wish that it would just go away. For 2015, The Tax Policy Center projects that AMT will impact 4.1 million taxpayers and generate $28.2 billion – so it is safe to assume that Congress will not loosen... More →
"[KOS is] friendly, approachable, and always willing to help me find the answer to a question." - Joan Meyer La James International College