The five most wealthy U.S.-based physician billionaires on Forbes' real-time billionaire tracker are varying degrees of self-made.
Forbes scores each of its listed billionaires with a "self-made" score ranging from one to 10, with one through five indicating someone who inherited some or all of his or her fortune; while six through 10 are for those who built their company or established a fortune on his or her own.
Below are the five richest U.S. physician billionaires with self-made scores of six or higher and how they made their fortunes.
1. Thomas Frist, Jr., MD & family
Net worth: $21.3 billion
Self-made score: 7
How they made their fortune: Dr. Frist, a former Air Force flight surgeon, founded HCA Healthcare with his father in 1968. He owns more than 20 percent of the company. Although he does not hold an executive position at HCA, his sons are board members.
Net worth: $5.1 billion
Self-made score: 9
How they made their fortune: Dr. Soon-Shiong invented the cancer drug Abraxane, which treats pancreatic cancer. He sold his drug companies in 2008 for a combined $9.1 billion. He owns NantWorks, a network of healthcare startups, owns The Los Angeles Times and San Diego Tribune, and has stakes in Tribune Publishing and the Los Angeles Lakers.
Net worth: $3 billion
Self-made score: 8
How they made their fortune: Dr. Schleifer co-founded drugmaker Regeneron in 1988 and remains CEO of the Tarrytown, N.Y.-based company. Regeneron has developed six FDA-approved medications, including Eylea, a treatment for macular degeneration that was valued at $4.6 billion in 2019.
Net worth: $2.3 billion
Self-made score: No score given, listed as self-made
How they made their fortune: Dr. Troendle is the CEO of Medpace, a clinical research company he founded in Cincinnati in 1992. He has served on the boards of several public and private healthcare companies.
Net worth: $1.9 billion
Self-made score: 8
How they made their fortune: Dr. Frost joined Key Pharmaceuticals in 1972, where he reformulated its asthma drug and sold the company for $836 million. He then founded Ivax, a generic drugmaker, in 1987, which he sold to Teva Pharmaceuticals for $7.6 billion in 2005. He now runs diagnostics-maker Opko Health.
Editor's note: Live net worth data collected Sept. 18.