Margaret Baker

About Me

Margaret "Peggy" Baker is a shareholder of Illinois-based medical supplies giant Medline, which her father Jim Mills and uncle Jon Mills founded in 1966. The extended Mills family, which includes four other billionaires, owns roughly 17% of the company, which IPO'd on the Nasdaq in December 2025 and ended its first trading day with a market cap of more than $55 billion. The Mills family previously sold 79% of Medline to a group of private equity firms in a leveraged buyout that valued the company at more than $30 billion in 2021. Baker's brother Charlie Mills served as Medline's CEO for 26 years until 2023, while her cousin Andy Mills served as president during that same period. Charlie still serves as chairman and Andy still sits on the board. Andy Mills' brother-in-law Jim Abrams served as chief operating officer of Medline from 1997 to 2023. The company is now run by non-family executives.