Wayne Kocourek Net Worth: Best Estimates and How They’re Calculated

Wayne Kocourek's net worth in 2026 is estimated in the range of $150 million to $250 million, with the lower bound anchored by publicly verifiable data from his family foundation's IRS filings. The Wayne and Nan Kocourek Foundation alone reported net assets of over $133 million for fiscal year 2023, and that figure doesn't include the private investment portfolio and personal assets he holds outside the foundation. So while there's no single audited number floating around, the publicly available evidence points firmly to nine-figure wealth.

Who is Wayne Kocourek?

Wayne C. Kocourek is a Chicago-area private equity investor and principal of Mid Oaks Investments LLC, a firm he has run since 1986. He is based in Barrington Hills, Illinois, and his name surfaces in searches largely because of his philanthropic profile and the scale of the foundation he co-founded with his wife Nan Parks Kocourek in 2015. He is not a celebrity in the entertainment sense, but his family's name is attached to a 30,000-square-foot animal medical center on Chicago's Southwest Side (the Nan and Wayne Kocourek Medical Center at PAWS Chicago), which draws public attention and search interest.

Unlike politicians or entertainers whose financial disclosures are routine, Kocourek operates in the lower-profile world of principal investing, meaning he invests his own capital rather than managing outside funds. That makes him harder to research than a fund manager with SEC filings, but the foundation's mandatory IRS disclosures fill in a significant portion of the picture.

The best estimate: what the numbers actually say

The most defensible floor for Kocourek's net worth comes directly from IRS Form 990-PF filings for the Wayne and Nan Kocourek Foundation. For fiscal year ending December 2023, the foundation reported net assets of $133,650,130 and net income of $102,106,633 for that year alone. Revenue for that period came in at $111,313,699, driven primarily by contributions received and investment returns.

A separate aggregator, Instrumentl, using digitized 990-PF data updated through May 2026, puts total foundation assets at $124,935,053 with total giving of $15,335,895. The slight difference between these figures reflects different fiscal year snapshots, not contradictory data. Both paint the same picture: this is a foundation with assets well above $120 million.

Here is the critical interpretation point: a private foundation of this size almost always reflects wealth held outside it. Founders typically do not move the majority of their personal net worth into a charitable vehicle. The foundation is a wealth management and philanthropic tool, not a full accounting of everything Kocourek owns. That is why the estimate range extends well above the foundation's balance sheet. A conservative working estimate of $150 million to $250 million is reasonable given the foundation assets alone exceed $130 million and his four-decade investment career has continued generating returns.

Where the money comes from

Mid Oaks Investments and private equity

Mid Oaks Investments is the core engine. Founded in 1986, it operates as a private investment firm deploying the principals' own capital into private equity deals, primarily in manufacturing and industrial sectors. The firm targets companies with $25 million to $250 million in annual sales, a sweet spot for control buyouts and growth investments where returns can be substantial without the overhead of managing a large institutional fund.

One known exit: Kocourek sold Applied Industrial Materials Corp. in Chicago in 1997. That transaction would have generated a meaningful liquidity event and seeded the capital base that Mid Oaks has compounded since. Forty years of private equity investing, even at a small-to-mid-market scale, can accumulate to very large numbers when returns are reinvested consistently.

Foundation compensation

Wayne Kocourek draws a reported trustee compensation of $165,755 from the foundation, while his wife Nan, who serves as CEO, draws $150,000. These are modest figures relative to the foundation's asset base and represent a small fraction of his overall income picture. They are worth noting because they appear in the public IRS filing and are often the only confirmed compensation data available for someone in his position.

Assets and lifestyle signals

Barrington Hills, Illinois, where Kocourek is based, is one of the wealthiest communities in the greater Chicago area. Property values there routinely run into the multi-million dollar range for estate-sized lots, which is consistent with the wealth profile the financial data suggests. Beyond that, the most visible asset associated with his name is the Nan and Wayne Kocourek Medical Center at PAWS Chicago: a 30,000-square-foot veterinary facility on Chicago's Southwest Side. Named philanthropic giving at this scale (a major institutional building) indicates both significant capacity and a preference for directed, high-impact giving rather than flashy personal consumption.

There are no publicly reported yacht purchases, aircraft registrations, or art auction appearances connected to his name in the research record, which is consistent with the profile of a private-market investor who built wealth quietly over decades rather than through a public-facing career. That does not mean those assets do not exist; it simply means they are not documented in accessible public records.

How net worth estimates like this are calculated

For a private figure like Kocourek, the methodology is different from estimating a celebrity's wealth. There are no stock option grants, no publicly traded equity stakes, and no entertainment contracts to analyze. Instead, researchers work from several data layers.

1. IRS Form 990-PF filings: Private foundations must file these annually with the IRS, and the documents are public. They show assets, liabilities, income, expenses, grants paid, and officer compensation. For Kocourek, these filings are the single most reliable primary data source.
2. Secondary aggregators: Sites like ProPublica's Nonprofit Explorer, Instrumentl, Cause IQ, and Grantable digitize and index 990 filings to make them searchable. They are useful shortcuts but always lag the primary documents by months and occasionally introduce transcription differences.
3. Business registry data: Sources like Owler and Massinvestor aggregate company information, including founding dates and executive titles. These are useful for confirming career context but are not financial statements.
4. Comparable wealth benchmarks: Knowing that someone has operated a private equity firm for 40 years targeting mid-market industrial companies allows analysts to apply industry return benchmarks to produce a range estimate for private investment portfolios.
5. Real estate and public records: Property records in Cook and Lake counties (Illinois) are publicly searchable and can confirm asset holdings, though they require direct lookup.

The honest caveat here is that private investors have no obligation to disclose personal balance sheets. The estimate range of $150 million to $250 million is probabilistic, not audited. If you are looking specifically for William Kozyra net worth updates, you will need to cross-check the latest primary reporting and credible aggregators, since figures can shift with new disclosures and market movements. The foundation data gives a reliable floor. The ceiling is speculative but grounded in the scale and duration of his investment activity. Different net worth aggregator sites may publish different figures because they weight these inputs differently or rely on older snapshots.

How this compares to other private investor profiles

Kocourek's profile is meaningfully different from the public-facing figures often covered on net worth reference sites. Kocourek's profile is meaningfully different from the public-facing figures often covered on net worth reference sites, such as the type of coverage people look for with nick kozmin net worth. Coach K net worth searches often refer to high-visibility sports careers, but Wayne Kocourek's estimate is instead anchored in private equity and foundation filings. Someone like a sports coach or fitness personality (like those covered in profiles of Coach Kozak, Coach K, or similar names that come up in related searches) builds wealth through a public career with trackable income streams: salaries, endorsements, media deals. If you are also comparing figures like coach kozak and claudia net worth, the key is still to separate public, income-based reporting from the kind of private capital allocation shown in Kocourek’s filings. Kocourek's wealth is built entirely through private capital allocation, which is harder to document but also tends to be more concentrated and less volatile once established.

How to find updated numbers and verify the estimate yourself

Because foundation filings update annually and private investment values shift with markets, the smartest move is to go directly to primary sources rather than relying on any single net worth estimate (including this one). Here is exactly how to do it.

1. Go to ProPublica Nonprofit Explorer and search 'Wayne and Nan Kocourek Foundation' (EIN: 47-6807414). Download the most recent 990-PF PDF directly. Look at Part II for balance sheet data: total assets, total liabilities, and net assets. This gives you the verified foundation floor.
2. Cross-reference with Instrumentl or Cause IQ for a quick read on the same filing, but always confirm against the actual document if the number is important to you.
3. Check Illinois Secretary of State business filings for Mid Oaks Investments LLC to confirm the entity is still active and to see any recent amendments (this won't show financials but confirms operational status).
4. Search Cook County and Lake County property records online for any real estate holdings under Wayne C. Kocourek or related entities. Illinois property records are public.
5. Set a Google Alert for 'Wayne Kocourek' or 'Mid Oaks Investments' to catch any new press coverage, philanthropic announcements, or business news that might update the picture.
6. Revisit this site's profile page for updated estimates as new 990-PF filings are processed, typically in the May to July window each year after the foundation's annual filing deadline.

The next 990-PF covering fiscal year 2024 would typically be filed by mid-2025 or extended into 2026. Given that the June 2025 filing covered FY2023, the FY2024 filing may already be available or will appear shortly. Checking ProPublica around mid-2026 should surface that document and give you the most current verified foundation asset figure to anchor any updated estimate.