Meet The New Billionaires Behind Medline’s Blockbuster IPO

Key Concepts

• Initial Public Offering (IPO): The first sale of stock by a private company to the public.
• Market Capitalization: The total value of a company's outstanding shares of stock.
• Leveraged Buyout (LBO): An acquisition of another company using a significant amount of borrowed money (leverage) to meet the cost of acquisition.
• Private Equity Firms: Investment management companies that provide financial backing and make investments in the private equity of companies.
• Mosart Holdco: The entity through which the Mills family holds its remaining stake in Medline after the private equity deal and IPO.
• Mills Clan: The founding family of Medline, whose members became billionaires following the company's IPO.

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Medline's Blockbuster IPO and New Billionaires

Medical supplies giant Medline went public in December 2025, marking one of the year's largest initial public offerings. On its first trading day, the company's stock soared by 41%, closing with a market capitalization exceeding $55 billion. This significant event, coupled with newly disclosed ownership records, propelled at least five members of the Illinois-based Mills family onto Forbes's billionaires list for the first time.

The five new billionaires are all children of Medline's co-founders, brothers Jim and John Mills:

• Charlie Mills: Jim's son, who served as CEO for 26 years until 2023, is estimated to be worth $10.9 billion. He remains chairman and a director of the publicly traded company.
• Andy Mills: John's son, who served as president during the same period, is estimated at $5.4 billion. He also remains a director.
• Wendy Abrams: John's daughter, who has no role at the company, is worth an estimated $4.5 billion. Her husband, Jim Abrams, served as Chief Operating Officer from 1997 to 2023.
• Nancy Mills Barnett: Andy's sister, estimated at $4.2 billion.
• Margaret Baker: Charlie's sister, estimated at $3.8 billion.

The combined wealth of the Mills family is estimated by Forbes to be $31 billion. A spokesperson for the family declined to comment on these figures.

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The Mills Family Fortune and Ownership Structure

Medline, founded in 1966, remained 100% family-owned for nearly 55 years. In 2021, the next generation of the Mills family sold 79% of the company to a consortium of private equity firms, primarily led by Blackstone and Carlyle, in a leveraged buyout. This transaction valued Medline at over $30 billion. Forbes estimates that the family netted $18 billion after taxes from this sale, retaining a 21% stake prior to the IPO.

During the IPO, the family did not sell any additional shares, but their ownership was diluted to approximately 17%. The breakdown of the Mills family's fortune was previously private but became public with Medline's IPO prospectus. This document revealed that the family's remaining stake is held through an entity named Mosart Holdco. Forbes's analysis indicates that 91% of Mosart Holdco is owned by trusts established in the names of the five family members now identified as billionaires. Specifically, trusts tied to Charlie, Andy, Nancy, Wendy, and Peggy own 37%, 18%, 14%, 12%, and 11% of Mosart Holdco, respectively.

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Medline's Financial Performance and Growth

Since the private equity firms took over in 2021, Medline has experienced substantial growth. The company's revenue has increased by nearly 50%, rising from $17.5 billion in 2020 to $25.5 billion in 2024. In 2024, Medline reported a net income of $1.2 billion. The company is on track to surpass this performance in 2025, having posted $1 billion in profit on $20.6 billion of sales in the first nine months of the year.

Medline also rose to national prominence during the COVID-19 pandemic. The surge in demand for masks, disinfectants, and other medical supplies led to a 26% jump in sales in a single year, highlighting the company's critical role in healthcare supply chains.

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Historical Context and Evolution of Medline

Medline's origins trace back to 1910 when Al Mills, the great-grandfather of Charlie and Andy Mills, moved from Arkansas to Chicago and began selling handmade butcher aprons. His business expanded into surgeon's gowns after a nun inquired about hospital garments. Andy Mills noted in 2020, "At the time, a butcher's apron and a surgeon's gown were the same exact material."

In 1912, Al Mills founded Mills Hospital Supplies, which was later passed to his son, Irving. Under Irving's leadership, the family pioneered blue and green operating room fabrics and introduced pink and blue striped blankets for newborns. Irving eventually sold the business in 1961.

Five years later, in 1966, Irving's sons, John and Jim Mills, launched Medline with a $500,000 investment from their father. By the end of their first year, the brothers achieved $1 million in revenue, equivalent to $10 million today. Medline briefly went public in 1972 before being taken private again. By 1997, when Charlie and Andy Mills, along with Jim Abrams, assumed leadership, sales had grown to over $500 million, which is equivalent to $1 billion today.

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Family Legacy and Philanthropy

Despite being one of America's wealthiest families, the Mills clan is known for its privacy. However, they have garnered attention for their philanthropic endeavors. Jim Abrams, a former COO and husband to Wendy Abrams, shared a perspective on the company's culture, stating, "There's a level of modesty in the company that we don't walk around with any swagger."

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Conclusion

Medline's recent IPO in December 2025 marked a pivotal moment, transforming the privately held medical supplies giant into a publicly traded entity with a market capitalization exceeding $55 billion. This event not only underscored Medline's significant growth, particularly since its 2021 leveraged buyout by private equity firms and its crucial role during the COVID-19 pandemic, but also unveiled the substantial wealth of the Mills family. The IPO prospectus revealed the family's intricate ownership structure through Mosart Holdco, propelling five key members of the Mills clan onto Forbes's billionaires list. From its humble beginnings in 1910 selling butcher aprons to its current status as a multi-billion-dollar enterprise, Medline's journey highlights a century of family entrepreneurship, strategic financial maneuvers, and sustained market leadership, all while maintaining a reputation for privacy and philanthropy.